diff --git a/Gemfile b/Gemfile
index bde2f2e..d6768cc 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,7 +2,7 @@ source 'https://rubygems.org'
 
 
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
-gem 'rails', '4.2.2'
+gem 'rails', '~> 5.0'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3'
 # Use SCSS for stylesheets
diff --git a/Gemfile.lock b/Gemfile.lock
index e1b93b6..473c297 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,177 +1,187 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    actionmailer (4.2.2)
-      actionpack (= 4.2.2)
-      actionview (= 4.2.2)
-      activejob (= 4.2.2)
+    actioncable (5.0.0.1)
+      actionpack (= 5.0.0.1)
+      nio4r (~> 1.2)
+      websocket-driver (~> 0.6.1)
+    actionmailer (5.0.0.1)
+      actionpack (= 5.0.0.1)
+      actionview (= 5.0.0.1)
+      activejob (= 5.0.0.1)
       mail (~> 2.5, >= 2.5.4)
-      rails-dom-testing (~> 1.0, >= 1.0.5)
-    actionpack (4.2.2)
-      actionview (= 4.2.2)
-      activesupport (= 4.2.2)
-      rack (~> 1.6)
-      rack-test (~> 0.6.2)
-      rails-dom-testing (~> 1.0, >= 1.0.5)
-      rails-html-sanitizer (~> 1.0, >= 1.0.1)
-    actionview (4.2.2)
-      activesupport (= 4.2.2)
+      rails-dom-testing (~> 2.0)
+    actionpack (5.0.0.1)
+      actionview (= 5.0.0.1)
+      activesupport (= 5.0.0.1)
+      rack (~> 2.0)
+      rack-test (~> 0.6.3)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.0.2)
+    actionview (5.0.0.1)
+      activesupport (= 5.0.0.1)
       builder (~> 3.1)
       erubis (~> 2.7.0)
-      rails-dom-testing (~> 1.0, >= 1.0.5)
-      rails-html-sanitizer (~> 1.0, >= 1.0.1)
-    activejob (4.2.2)
-      activesupport (= 4.2.2)
-      globalid (>= 0.3.0)
-    activemodel (4.2.2)
-      activesupport (= 4.2.2)
-      builder (~> 3.1)
-    activerecord (4.2.2)
-      activemodel (= 4.2.2)
-      activesupport (= 4.2.2)
-      arel (~> 6.0)
-    activesupport (4.2.2)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.0.2)
+    activejob (5.0.0.1)
+      activesupport (= 5.0.0.1)
+      globalid (>= 0.3.6)
+    activemodel (5.0.0.1)
+      activesupport (= 5.0.0.1)
+    activerecord (5.0.0.1)
+      activemodel (= 5.0.0.1)
+      activesupport (= 5.0.0.1)
+      arel (~> 7.0)
+    activesupport (5.0.0.1)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (~> 0.7)
-      json (~> 1.7, >= 1.7.7)
       minitest (~> 5.1)
-      thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    arel (6.0.0)
-    bcrypt (3.1.10)
+    arel (7.1.1)
+    bcrypt (3.1.11)
     binding_of_caller (0.7.2)
       debug_inspector (>= 0.0.1)
     builder (3.2.2)
-    byebug (5.0.0)
-      columnize (= 0.9.0)
-    coffee-rails (4.1.0)
+    byebug (9.0.5)
+    coffee-rails (4.1.1)
       coffee-script (>= 2.2.0)
-      railties (>= 4.0.0, < 5.0)
+      railties (>= 4.0.0, < 5.1.x)
     coffee-script (2.4.1)
       coffee-script-source
       execjs
-    coffee-script-source (1.9.1.1)
-    columnize (0.9.0)
+    coffee-script-source (1.10.0)
+    concurrent-ruby (1.0.2)
     debug_inspector (0.0.2)
-    devise (3.5.1)
+    devise (4.2.0)
       bcrypt (~> 3.0)
       orm_adapter (~> 0.1)
-      railties (>= 3.2.6, < 5)
+      railties (>= 4.1.0, < 5.1)
       responders
-      thread_safe (~> 0.1)
       warden (~> 1.2.3)
     diff-lcs (1.2.5)
     erubis (2.7.0)
-    execjs (2.5.2)
-    faker (1.4.3)
+    execjs (2.7.0)
+    faker (1.6.6)
       i18n (~> 0.5)
-    globalid (0.3.5)
+    globalid (0.3.7)
       activesupport (>= 4.1.0)
     i18n (0.7.0)
-    jbuilder (2.3.0)
-      activesupport (>= 3.0.0, < 5)
+    jbuilder (2.6.0)
+      activesupport (>= 3.0.0, < 5.1)
       multi_json (~> 1.2)
-    jquery-rails (4.0.4)
-      rails-dom-testing (~> 1.0)
+    jquery-rails (4.2.1)
+      rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
     json (1.8.3)
-    kaminari (0.16.3)
+    kaminari (0.17.0)
       actionpack (>= 3.0.0)
       activesupport (>= 3.0.0)
-    loofah (2.0.2)
+    loofah (2.0.3)
       nokogiri (>= 1.5.9)
-    mail (2.6.3)
-      mime-types (>= 1.16, < 3)
-    mime-types (2.6.1)
-    mini_portile (0.6.2)
-    minitest (5.7.0)
-    multi_json (1.11.1)
-    nokogiri (1.6.6.2)
-      mini_portile (~> 0.6.0)
+    mail (2.6.4)
+      mime-types (>= 1.16, < 4)
+    method_source (0.8.2)
+    mime-types (3.1)
+      mime-types-data (~> 3.2015)
+    mime-types-data (3.2016.0521)
+    mini_portile2 (2.1.0)
+    minitest (5.9.0)
+    multi_json (1.12.1)
+    nio4r (1.2.1)
+    nokogiri (1.6.8)
+      mini_portile2 (~> 2.1.0)
+      pkg-config (~> 1.1.7)
     orm_adapter (0.5.0)
-    rack (1.6.4)
+    pkg-config (1.1.7)
+    rack (2.0.1)
     rack-test (0.6.3)
       rack (>= 1.0)
-    rails (4.2.2)
-      actionmailer (= 4.2.2)
-      actionpack (= 4.2.2)
-      actionview (= 4.2.2)
-      activejob (= 4.2.2)
-      activemodel (= 4.2.2)
-      activerecord (= 4.2.2)
-      activesupport (= 4.2.2)
+    rails (5.0.0.1)
+      actioncable (= 5.0.0.1)
+      actionmailer (= 5.0.0.1)
+      actionpack (= 5.0.0.1)
+      actionview (= 5.0.0.1)
+      activejob (= 5.0.0.1)
+      activemodel (= 5.0.0.1)
+      activerecord (= 5.0.0.1)
+      activesupport (= 5.0.0.1)
       bundler (>= 1.3.0, < 2.0)
-      railties (= 4.2.2)
-      sprockets-rails
-    rails-deprecated_sanitizer (1.0.3)
-      activesupport (>= 4.2.0.alpha)
-    rails-dom-testing (1.0.6)
-      activesupport (>= 4.2.0.beta, < 5.0)
+      railties (= 5.0.0.1)
+      sprockets-rails (>= 2.0.0)
+    rails-dom-testing (2.0.1)
+      activesupport (>= 4.2.0, < 6.0)
       nokogiri (~> 1.6.0)
-      rails-deprecated_sanitizer (>= 1.0.1)
-    rails-html-sanitizer (1.0.2)
+    rails-html-sanitizer (1.0.3)
       loofah (~> 2.0)
-    railties (4.2.2)
-      actionpack (= 4.2.2)
-      activesupport (= 4.2.2)
+    railties (5.0.0.1)
+      actionpack (= 5.0.0.1)
+      activesupport (= 5.0.0.1)
+      method_source
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
-    rake (10.4.2)
-    rdoc (4.2.0)
-    responders (2.1.0)
-      railties (>= 4.2.0, < 5)
-    rspec-core (3.3.2)
-      rspec-support (~> 3.3.0)
-    rspec-expectations (3.3.1)
+    rake (11.2.2)
+    rdoc (4.2.2)
+      json (~> 1.4)
+    responders (2.3.0)
+      railties (>= 4.2.0, < 5.1)
+    rspec-core (3.5.2)
+      rspec-support (~> 3.5.0)
+    rspec-expectations (3.5.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.3.0)
-    rspec-mocks (3.3.2)
+      rspec-support (~> 3.5.0)
+    rspec-mocks (3.5.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.3.0)
-    rspec-rails (3.3.3)
-      actionpack (>= 3.0, < 4.3)
-      activesupport (>= 3.0, < 4.3)
-      railties (>= 3.0, < 4.3)
-      rspec-core (~> 3.3.0)
-      rspec-expectations (~> 3.3.0)
-      rspec-mocks (~> 3.3.0)
-      rspec-support (~> 3.3.0)
-    rspec-support (3.3.0)
-    sass (3.4.15)
-    sass-rails (5.0.3)
-      railties (>= 4.0.0, < 5.0)
+      rspec-support (~> 3.5.0)
+    rspec-rails (3.5.2)
+      actionpack (>= 3.0)
+      activesupport (>= 3.0)
+      railties (>= 3.0)
+      rspec-core (~> 3.5.0)
+      rspec-expectations (~> 3.5.0)
+      rspec-mocks (~> 3.5.0)
+      rspec-support (~> 3.5.0)
+    rspec-support (3.5.0)
+    sass (3.4.22)
+    sass-rails (5.0.6)
+      railties (>= 4.0.0, < 6)
       sass (~> 3.1)
       sprockets (>= 2.8, < 4.0)
       sprockets-rails (>= 2.0, < 4.0)
-      tilt (~> 1.1)
+      tilt (>= 1.1, < 3)
     sdoc (0.4.1)
       json (~> 1.7, >= 1.7.7)
       rdoc (~> 4.0)
-    spring (1.3.6)
-    sprockets (3.2.0)
-      rack (~> 1.0)
-    sprockets-rails (2.3.2)
-      actionpack (>= 3.0)
-      activesupport (>= 3.0)
-      sprockets (>= 2.8, < 4.0)
-    sqlite3 (1.3.10)
+    spring (1.7.2)
+    sprockets (3.7.0)
+      concurrent-ruby (~> 1.0)
+      rack (> 1, < 3)
+    sprockets-rails (3.1.1)
+      actionpack (>= 4.0)
+      activesupport (>= 4.0)
+      sprockets (>= 3.0.0)
+    sqlite3 (1.3.11)
     thor (0.19.1)
     thread_safe (0.3.5)
-    tilt (1.4.1)
-    turbolinks (2.5.3)
-      coffee-rails
+    tilt (2.0.5)
+    turbolinks (5.0.1)
+      turbolinks-source (~> 5)
+    turbolinks-source (5.0.0)
     tzinfo (1.2.2)
       thread_safe (~> 0.1)
-    uglifier (2.7.1)
-      execjs (>= 0.3.0)
-      json (>= 1.8.0)
-    warden (1.2.3)
+    uglifier (3.0.2)
+      execjs (>= 0.3.0, < 3)
+    warden (1.2.6)
       rack (>= 1.0)
-    web-console (2.1.3)
+    web-console (2.3.0)
       activemodel (>= 4.0)
       binding_of_caller (>= 0.7.2)
       railties (>= 4.0)
       sprockets-rails (>= 2.0, < 4.0)
+    websocket-driver (0.6.4)
+      websocket-extensions (>= 0.1.0)
+    websocket-extensions (0.1.2)
 
 PLATFORMS
   ruby
@@ -184,7 +194,7 @@ DEPENDENCIES
   jbuilder (~> 2.0)
   jquery-rails
   kaminari
-  rails (= 4.2.2)
+  rails (~> 5.0)
   rspec-rails
   sass-rails (~> 5.0)
   sdoc (~> 0.4.0)
@@ -195,4 +205,4 @@ DEPENDENCIES
   web-console (~> 2.0)
 
 BUNDLED WITH
-   1.10.5
+   1.12.5
diff --git a/app/models/application_record.rb b/app/models/application_record.rb
new file mode 100644
index 0000000..71a1a03
--- /dev/null
+++ b/app/models/application_record.rb
@@ -0,0 +1,3 @@
+class ApplicationRecord < ActiveRecord::Base
+  self.abstract_class = true
+end
\ No newline at end of file
diff --git a/app/models/comment.rb b/app/models/comment.rb
index aed6653..831645a 100644
--- a/app/models/comment.rb
+++ b/app/models/comment.rb
@@ -1,4 +1,4 @@
-class Comment < ActiveRecord::Base
+class Comment < ApplicationRecord
 
   belongs_to :user
   belongs_to :message
diff --git a/app/models/message.rb b/app/models/message.rb
index e24a8b2..9a0196a 100644
--- a/app/models/message.rb
+++ b/app/models/message.rb
@@ -1,4 +1,4 @@
-class Message < ActiveRecord::Base
+class Message < ApplicationRecord
 
   belongs_to :user
 
diff --git a/app/models/user.rb b/app/models/user.rb
index 6d01aa9..3d95762 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -1,4 +1,4 @@
-class User < ActiveRecord::Base
+class User < ApplicationRecord
   # Include default devise modules. Others available are:
   # :confirmable, :lockable, :timeoutable and :omniauthable
   devise :database_authenticatable, :registerable,
diff --git a/bin/rails b/bin/rails
index 4d608ed..0739660 100755
--- a/bin/rails
+++ b/bin/rails
@@ -1,8 +1,4 @@
 #!/usr/bin/env ruby
-begin
-  load File.expand_path("../spring", __FILE__)
-rescue LoadError
-end
-APP_PATH = File.expand_path('../../config/application', __FILE__)
+APP_PATH = File.expand_path('../config/application', __dir__)
 require_relative '../config/boot'
 require 'rails/commands'
diff --git a/bin/rake b/bin/rake
index 8017a02..1724048 100755
--- a/bin/rake
+++ b/bin/rake
@@ -1,8 +1,4 @@
 #!/usr/bin/env ruby
-begin
-  load File.expand_path("../spring", __FILE__)
-rescue LoadError
-end
 require_relative '../config/boot'
 require 'rake'
 Rake.application.run
diff --git a/bin/setup b/bin/setup
index acdb2c1..e620b4d 100755
--- a/bin/setup
+++ b/bin/setup
@@ -1,29 +1,34 @@
 #!/usr/bin/env ruby
 require 'pathname'
+require 'fileutils'
+include FileUtils
 
 # path to your application root.
-APP_ROOT = Pathname.new File.expand_path('../../',  __FILE__)
+APP_ROOT = Pathname.new File.expand_path('../../', __FILE__)
 
-Dir.chdir APP_ROOT do
+def system!(*args)
+  system(*args) || abort("\n== Command #{args} failed ==")
+end
+
+chdir APP_ROOT do
   # This script is a starting point to setup your application.
-  # Add necessary setup steps to this file:
+  # Add necessary setup steps to this file.
 
-  puts "== Installing dependencies =="
-  system "gem install bundler --conservative"
-  system "bundle check || bundle install"
+  puts '== Installing dependencies =='
+  system! 'gem install bundler --conservative'
+  system('bundle check') || system!('bundle install')
 
   # puts "\n== Copying sample files =="
-  # unless File.exist?("config/database.yml")
-  #   system "cp config/database.yml.sample config/database.yml"
+  # unless File.exist?('config/database.yml')
+  #   cp 'config/database.yml.sample', 'config/database.yml'
   # end
 
   puts "\n== Preparing database =="
-  system "bin/rake db:setup"
+  system! 'bin/rails db:setup'
 
   puts "\n== Removing old logs and tempfiles =="
-  system "rm -f log/*"
-  system "rm -rf tmp/cache"
+  system! 'bin/rails log:clear tmp:clear'
 
   puts "\n== Restarting application server =="
-  system "touch tmp/restart.txt"
+  system! 'bin/rails restart'
 end
diff --git a/bin/update b/bin/update
new file mode 100755
index 0000000..a8e4462
--- /dev/null
+++ b/bin/update
@@ -0,0 +1,29 @@
+#!/usr/bin/env ruby
+require 'pathname'
+require 'fileutils'
+include FileUtils
+
+# path to your application root.
+APP_ROOT = Pathname.new File.expand_path('../../', __FILE__)
+
+def system!(*args)
+  system(*args) || abort("\n== Command #{args} failed ==")
+end
+
+chdir APP_ROOT do
+  # This script is a way to update your development environment automatically.
+  # Add necessary update steps to this file.
+
+  puts '== Installing dependencies =='
+  system! 'gem install bundler --conservative'
+  system('bundle check') || system!('bundle install')
+
+  puts "\n== Updating database =="
+  system! 'bin/rails db:migrate'
+
+  puts "\n== Removing old logs and tempfiles =="
+  system! 'bin/rails log:clear tmp:clear'
+
+  puts "\n== Restarting application server =="
+  system! 'bin/rails restart'
+end
diff --git a/config/application.rb b/config/application.rb
index 4d3aa47..b091193 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -1,4 +1,4 @@
-require File.expand_path('../boot', __FILE__)
+require_relative 'boot'
 
 require 'rails/all'
 
@@ -11,16 +11,5 @@ class Application < Rails::Application
     # Settings in config/environments/* take precedence over those specified here.
     # Application configuration should go into files in config/initializers
     # -- all .rb files in that directory are automatically loaded.
-
-    # Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
-    # Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.
-    # config.time_zone = 'Central Time (US & Canada)'
-
-    # The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded.
-    # config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
-    # config.i18n.default_locale = :de
-
-    # Do not swallow errors in after_commit/after_rollback callbacks.
-    config.active_record.raise_in_transactional_callbacks = true
   end
 end
diff --git a/config/boot.rb b/config/boot.rb
index 6b750f0..30f5120 100644
--- a/config/boot.rb
+++ b/config/boot.rb
@@ -1,3 +1,3 @@
-ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
+ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
 
 require 'bundler/setup' # Set up gems listed in the Gemfile.
diff --git a/config/cable.yml b/config/cable.yml
new file mode 100644
index 0000000..0bbde6f
--- /dev/null
+++ b/config/cable.yml
@@ -0,0 +1,9 @@
+development:
+  adapter: async
+
+test:
+  adapter: async
+
+production:
+  adapter: redis
+  url: redis://localhost:6379/1
diff --git a/config/environment.rb b/config/environment.rb
index ee8d90d..426333b 100644
--- a/config/environment.rb
+++ b/config/environment.rb
@@ -1,5 +1,5 @@
 # Load the Rails application.
-require File.expand_path('../application', __FILE__)
+require_relative 'application'
 
 # Initialize the Rails application.
 Rails.application.initialize!
diff --git a/config/environments/development.rb b/config/environments/development.rb
index b55e214..e64889c 100644
--- a/config/environments/development.rb
+++ b/config/environments/development.rb
@@ -9,13 +9,28 @@
   # Do not eager load code on boot.
   config.eager_load = false
 
-  # Show full error reports and disable caching.
-  config.consider_all_requests_local       = true
-  config.action_controller.perform_caching = false
+  # Show full error reports.
+  config.consider_all_requests_local = true
+
+  # Enable/disable caching. By default caching is disabled.
+  if Rails.root.join('tmp/caching-dev.txt').exist?
+    config.action_controller.perform_caching = true
+
+    config.cache_store = :memory_store
+    config.public_file_server.headers = {
+      'Cache-Control' => 'public, max-age=172800'
+    }
+  else
+    config.action_controller.perform_caching = false
+
+    config.cache_store = :null_store
+  end
 
   # Don't care if the mailer can't send.
   config.action_mailer.raise_delivery_errors = false
 
+  config.action_mailer.perform_caching = false
+
   # Print deprecation notices to the Rails logger.
   config.active_support.deprecation = :log
 
@@ -27,15 +42,13 @@
   # number of complex assets.
   config.assets.debug = true
 
-  # Asset digests allow you to set far-future HTTP expiration dates on all assets,
-  # yet still be able to expire them through the digest params.
-  config.assets.digest = true
-
-  # Adds additional error checking when serving assets at runtime.
-  # Checks for improperly declared sprockets dependencies.
-  # Raises helpful error messages.
-  config.assets.raise_runtime_errors = true
+  # Suppress logger output for asset requests.
+  config.assets.quiet = true
 
   # Raises error for missing translations
   # config.action_view.raise_on_missing_translations = true
+
+  # Use an evented file watcher to asynchronously detect changes in source code,
+  # routes, locales, etc. This feature depends on the listen gem.
+  # config.file_watcher = ActiveSupport::EventedFileUpdateChecker
 end
diff --git a/config/environments/production.rb b/config/environments/production.rb
index 5c1b32e..f710032 100644
--- a/config/environments/production.rb
+++ b/config/environments/production.rb
@@ -14,15 +14,9 @@
   config.consider_all_requests_local       = false
   config.action_controller.perform_caching = true
 
-  # Enable Rack::Cache to put a simple HTTP cache in front of your application
-  # Add `rack-cache` to your Gemfile before enabling this.
-  # For large-scale production use, consider using a caching reverse proxy like
-  # NGINX, varnish or squid.
-  # config.action_dispatch.rack_cache = true
-
   # Disable serving static files from the `/public` folder by default since
   # Apache or NGINX already handles this.
-  config.serve_static_files = ENV['RAILS_SERVE_STATIC_FILES'].present?
+  config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?
 
   # Compress JavaScripts and CSS.
   config.assets.js_compressor = :uglifier
@@ -31,16 +25,20 @@
   # Do not fallback to assets pipeline if a precompiled asset is missed.
   config.assets.compile = false
 
-  # Asset digests allow you to set far-future HTTP expiration dates on all assets,
-  # yet still be able to expire them through the digest params.
-  config.assets.digest = true
-
   # `config.assets.precompile` and `config.assets.version` have moved to config/initializers/assets.rb
 
+  # Enable serving of images, stylesheets, and JavaScripts from an asset server.
+  # config.action_controller.asset_host = 'http://assets.example.com'
+
   # Specifies the header that your server uses for sending files.
   # config.action_dispatch.x_sendfile_header = 'X-Sendfile' # for Apache
   # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for NGINX
 
+  # Mount Action Cable outside main process or domain
+  # config.action_cable.mount_path = nil
+  # config.action_cable.url = 'wss://example.com/cable'
+  # config.action_cable.allowed_request_origins = [ 'http://example.com', /http:\/\/example.*/ ]
+
   # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
   # config.force_ssl = true
 
@@ -49,16 +47,15 @@
   config.log_level = :debug
 
   # Prepend all log lines with the following tags.
-  # config.log_tags = [ :subdomain, :uuid ]
-
-  # Use a different logger for distributed setups.
-  # config.logger = ActiveSupport::TaggedLogging.new(SyslogLogger.new)
+  config.log_tags = [ :request_id ]
 
   # Use a different cache store in production.
   # config.cache_store = :mem_cache_store
 
-  # Enable serving of images, stylesheets, and JavaScripts from an asset server.
-  # config.action_controller.asset_host = 'http://assets.example.com'
+  # Use a real queuing backend for Active Job (and separate queues per environment)
+  # config.active_job.queue_adapter     = :resque
+  # config.active_job.queue_name_prefix = "help_exercise_#{Rails.env}"
+  config.action_mailer.perform_caching = false
 
   # Ignore bad email addresses and do not raise email delivery errors.
   # Set this to true and configure the email server for immediate delivery to raise delivery errors.
@@ -74,6 +71,16 @@
   # Use default logging formatter so that PID and timestamp are not suppressed.
   config.log_formatter = ::Logger::Formatter.new
 
+  # Use a different logger for distributed setups.
+  # require 'syslog/logger'
+  # config.logger = ActiveSupport::TaggedLogging.new(Syslog::Logger.new 'app-name')
+
+  if ENV["RAILS_LOG_TO_STDOUT"].present?
+    logger           = ActiveSupport::Logger.new(STDOUT)
+    logger.formatter = config.log_formatter
+    config.logger = ActiveSupport::TaggedLogging.new(logger)
+  end
+
   # Do not dump schema after migrations.
   config.active_record.dump_schema_after_migration = false
 end
diff --git a/config/environments/test.rb b/config/environments/test.rb
index 1c19f08..30587ef 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -12,9 +12,11 @@
   # preloads Rails for running tests, you may have to set it to true.
   config.eager_load = false
 
-  # Configure static file server for tests with Cache-Control for performance.
-  config.serve_static_files   = true
-  config.static_cache_control = 'public, max-age=3600'
+  # Configure public file server for tests with Cache-Control for performance.
+  config.public_file_server.enabled = true
+  config.public_file_server.headers = {
+    'Cache-Control' => 'public, max-age=3600'
+  }
 
   # Show full error reports and disable caching.
   config.consider_all_requests_local       = true
@@ -25,15 +27,13 @@
 
   # Disable request forgery protection in test environment.
   config.action_controller.allow_forgery_protection = false
+  config.action_mailer.perform_caching = false
 
   # Tell Action Mailer not to deliver emails to the real world.
   # The :test delivery method accumulates sent emails in the
   # ActionMailer::Base.deliveries array.
   config.action_mailer.delivery_method = :test
 
-  # Randomize the order test cases are executed.
-  config.active_support.test_order = :random
-
   # Print deprecation notices to the stderr.
   config.active_support.deprecation = :stderr
 
diff --git a/config/initializers/application_controller_renderer.rb b/config/initializers/application_controller_renderer.rb
new file mode 100644
index 0000000..51639b6
--- /dev/null
+++ b/config/initializers/application_controller_renderer.rb
@@ -0,0 +1,6 @@
+# Be sure to restart your server when you modify this file.
+
+# ApplicationController.renderer.defaults.merge!(
+#   http_host: 'example.org',
+#   https: false
+# )
diff --git a/config/initializers/cookies_serializer.rb b/config/initializers/cookies_serializer.rb
index 7f70458..5a6a32d 100644
--- a/config/initializers/cookies_serializer.rb
+++ b/config/initializers/cookies_serializer.rb
@@ -1,3 +1,5 @@
 # Be sure to restart your server when you modify this file.
 
+# Specify a serializer for the signed and encrypted cookie jars.
+# Valid options are :json, :marshal, and :hybrid.
 Rails.application.config.action_dispatch.cookies_serializer = :json
diff --git a/config/initializers/new_framework_defaults.rb b/config/initializers/new_framework_defaults.rb
new file mode 100644
index 0000000..f6e7233
--- /dev/null
+++ b/config/initializers/new_framework_defaults.rb
@@ -0,0 +1,23 @@
+# Be sure to restart your server when you modify this file.
+#
+# This file contains migration options to ease your Rails 5.0 upgrade.
+#
+# Once upgraded flip defaults one by one to migrate to the new default.
+#
+# Read the Rails 5.0 release notes for more info on each option.
+
+# Enable per-form CSRF tokens. Previous versions had false.
+Rails.application.config.action_controller.per_form_csrf_tokens = false
+
+# Enable origin-checking CSRF mitigation. Previous versions had false.
+Rails.application.config.action_controller.forgery_protection_origin_check = false
+
+# Make Ruby 2.4 preserve the timezone of the receiver when calling `to_time`.
+# Previous versions had false.
+ActiveSupport.to_time_preserves_timezone = false
+
+# Require `belongs_to` associations by default. Previous versions had false.
+Rails.application.config.active_record.belongs_to_required_by_default = false
+
+# Do not halt callback chains when a callback returns false. Previous versions had true.
+ActiveSupport.halt_callback_chains_on_return_false = true
diff --git a/config/initializers/session_store.rb b/config/initializers/session_store.rb
index 12c6571..397845d 100644
--- a/config/initializers/session_store.rb
+++ b/config/initializers/session_store.rb
@@ -1,3 +1,3 @@
 # Be sure to restart your server when you modify this file.
 
-Rails.application.config.session_store :cookie_store, key: '_help-exercise_session'
+Rails.application.config.session_store :cookie_store, key: '_help_exercise_session'
diff --git a/config/initializers/wrap_parameters.rb b/config/initializers/wrap_parameters.rb
index 33725e9..bbfc396 100644
--- a/config/initializers/wrap_parameters.rb
+++ b/config/initializers/wrap_parameters.rb
@@ -5,10 +5,10 @@
 
 # Enable parameter wrapping for JSON. You can disable this by setting :format to an empty array.
 ActiveSupport.on_load(:action_controller) do
-  wrap_parameters format: [:json] if respond_to?(:wrap_parameters)
+  wrap_parameters format: [:json]
 end
 
 # To enable root element in JSON for ActiveRecord objects.
 # ActiveSupport.on_load(:active_record) do
-#  self.include_root_in_json = true
+#   self.include_root_in_json = true
 # end
diff --git a/config/puma.rb b/config/puma.rb
new file mode 100644
index 0000000..c7f311f
--- /dev/null
+++ b/config/puma.rb
@@ -0,0 +1,47 @@
+# Puma can serve each request in a thread from an internal thread pool.
+# The `threads` method setting takes two numbers a minimum and maximum.
+# Any libraries that use thread pools should be configured to match
+# the maximum value specified for Puma. Default is set to 5 threads for minimum
+# and maximum, this matches the default thread size of Active Record.
+#
+threads_count = ENV.fetch("RAILS_MAX_THREADS") { 5 }.to_i
+threads threads_count, threads_count
+
+# Specifies the `port` that Puma will listen on to receive requests, default is 3000.
+#
+port        ENV.fetch("PORT") { 3000 }
+
+# Specifies the `environment` that Puma will run in.
+#
+environment ENV.fetch("RAILS_ENV") { "development" }
+
+# Specifies the number of `workers` to boot in clustered mode.
+# Workers are forked webserver processes. If using threads and workers together
+# the concurrency of the application would be max `threads` * `workers`.
+# Workers do not work on JRuby or Windows (both of which do not support
+# processes).
+#
+# workers ENV.fetch("WEB_CONCURRENCY") { 2 }
+
+# Use the `preload_app!` method when specifying a `workers` number.
+# This directive tells Puma to first boot the application and load code
+# before forking the application. This takes advantage of Copy On Write
+# process behavior so workers use less memory. If you use this option
+# you need to make sure to reconnect any threads in the `on_worker_boot`
+# block.
+#
+# preload_app!
+
+# The code in the `on_worker_boot` will be called if you are using
+# clustered mode by specifying a number of `workers`. After each worker
+# process is booted this block will be run, if you are using `preload_app!`
+# option you will want to use this block to reconnect to any threads
+# or connections that may have been created at application boot, Ruby
+# cannot share connections between processes.
+#
+# on_worker_boot do
+#   ActiveRecord::Base.establish_connection if defined?(ActiveRecord)
+# end
+
+# Allow puma to be restarted by `rails restart` command.
+plugin :tmp_restart
diff --git a/config/routes.rb b/config/routes.rb
index 74d4dbf..d38caa7 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -1,62 +1,10 @@
 Rails.application.routes.draw do
+  # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
   devise_for :users
 
   resources :messages do
     resources :comments
   end
 
-  # The priority is based upon order of creation: first created -> highest priority.
-  # See how all your routes lay out with "rake routes".
-
-  # You can have the root of your site routed with "root"
   root 'messages#index'
-
-  # Example of regular route:
-  #   get 'products/:id' => 'catalog#view'
-
-  # Example of named route that can be invoked with purchase_url(id: product.id)
-  #   get 'products/:id/purchase' => 'catalog#purchase', as: :purchase
-
-  # Example resource route (maps HTTP verbs to controller actions automatically):
-  #   resources :products
-
-  # Example resource route with options:
-  #   resources :products do
-  #     member do
-  #       get 'short'
-  #       post 'toggle'
-  #     end
-  #
-  #     collection do
-  #       get 'sold'
-  #     end
-  #   end
-
-  # Example resource route with sub-resources:
-  #   resources :products do
-  #     resources :comments, :sales
-  #     resource :seller
-  #   end
-
-  # Example resource route with more complex sub-resources:
-  #   resources :products do
-  #     resources :comments
-  #     resources :sales do
-  #       get 'recent', on: :collection
-  #     end
-  #   end
-
-  # Example resource route with concerns:
-  #   concern :toggleable do
-  #     post 'toggle'
-  #   end
-  #   resources :posts, concerns: :toggleable
-  #   resources :photos, concerns: :toggleable
-
-  # Example resource route within a namespace:
-  #   namespace :admin do
-  #     # Directs /admin/products/* to Admin::ProductsController
-  #     # (app/controllers/admin/products_controller.rb)
-  #     resources :products
-  #   end
-end
+end
\ No newline at end of file
diff --git a/config/secrets.yml b/config/secrets.yml
index ee9a314..5f47ce3 100644
--- a/config/secrets.yml
+++ b/config/secrets.yml
@@ -5,16 +5,16 @@
 
 # Make sure the secret is at least 30 characters and all random,
 # no regular words or you'll be exposed to dictionary attacks.
-# You can use `rake secret` to generate a secure secret key.
+# You can use `rails secret` to generate a secure secret key.
 
 # Make sure the secrets in this file are kept private
 # if you're sharing your code publicly.
 
 development:
-  secret_key_base: b6f8f5ab6bf1110e0c4f1033aa9b5251272d6fdb18dd139ab5304b36b2018d43afec288186f262b11927570c62efe6bd87c537b849174ad8d3d75a91f7038e29
+  secret_key_base: 59f0bc6ec73ea1119990e688703a12b15b4193a131010bc7bc3c5e4e19e2fbb945aa46e3b7bc31fa78f3da66bb0f3b6cf0b6393bb7ecc19568aefc9aed181b27
 
 test:
-  secret_key_base: e9c39890fb67cb6aa6290e193db88f8f32719888c69be93858f9929df251fc3a8cc93ba1753c5f2b1d4487adae6ec0a06ed4c28d382e2362e8203bc8c6919de9
+  secret_key_base: d4a57e48f8ed2f0f2aba5a9b3ec8ea49dcd0a19f933bfc5d1f43a05d717e2b1a350f5f1b48c0e8633d60bd4832fce8f3857ec9bcecbc0ba321396fa6bc689440
 
 # Do not keep production secrets in the repository,
 # instead read values from the environment.
diff --git a/config/spring.rb b/config/spring.rb
new file mode 100644
index 0000000..c9119b4
--- /dev/null
+++ b/config/spring.rb
@@ -0,0 +1,6 @@
+%w(
+  .ruby-version
+  .rbenv-vars
+  tmp/restart.txt
+  tmp/caching-dev.txt
+).each { |path| Spring.watch(path) }
diff --git a/db/schema.rb b/db/schema.rb
index ef7b5c0..7060616 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -1,4 +1,3 @@
-# encoding: UTF-8
 # This file is auto-generated from the current state of the database. Instead
 # of editing this file, please use the migrations feature of Active Record to
 # incrementally modify your database, and then regenerate this schema definition.
@@ -19,10 +18,9 @@
     t.integer  "message_id"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.index ["message_id"], name: "index_comments_on_message_id"
   end
 
-  add_index "comments", ["message_id"], name: "index_comments_on_message_id"
-
   create_table "messages", force: :cascade do |t|
     t.string   "title"
     t.text     "content"
@@ -31,11 +29,10 @@
     t.datetime "created_at",                        null: false
     t.datetime "updated_at",                        null: false
     t.string   "status",        default: "pending"
+    t.index ["status"], name: "index_messages_on_status"
+    t.index ["user_id"], name: "index_messages_on_user_id"
   end
 
-  add_index "messages", ["status"], name: "index_messages_on_status"
-  add_index "messages", ["user_id"], name: "index_messages_on_user_id"
-
   create_table "users", force: :cascade do |t|
     t.string   "email",                  default: "", null: false
     t.string   "encrypted_password",     default: "", null: false
@@ -49,9 +46,8 @@
     t.string   "last_sign_in_ip"
     t.datetime "created_at",                          null: false
     t.datetime "updated_at",                          null: false
+    t.index ["email"], name: "index_users_on_email", unique: true
+    t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true
   end
 
-  add_index "users", ["email"], name: "index_users_on_email", unique: true
-  add_index "users", ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true
-
 end