Setup

You should be able to install MongoDB with Brew using brew install mongodb
From there, as described below with Redis, follow the instructions to run MongoDB at login and at that moment. (Sorry, I've already installed it, so not sure what the exact commands are.)
Create a 'data' directory within your Lounge project. This is where your MongoDB data will be stored. data is included in your .gitignore file so it won't be included in your changes.
Run mongod --dbpath data (you will need to do this every time you work - maybe, but maybe not if you run MongoDB at login. Try not doing this, if your server doesn't run, then do it).
Running mongod will open up the Mongo shell which will allow you to run queries such as db.events.find({}) which can be useful for inspecting or altering data in your DB. Some intro info is available here.

Run brew install redis
Then run ln -sfv /usr/local/opt/redis/*.plist ~/Library/LaunchAgents so it will launch redis at login
Run launchctl load ~/Library/LaunchAgents/homebrew.mxcl.redis.plist to load redis right away
Edit your /usr/local/etc/redis.conf file, uncommenting the file with requirepass and setting the password to evanlounge, e.g., requirepass evanlounge. Additionally, set the port line to be port 6380.
Run Redis with redis-server /usr/local/etc/redis.conf. You will need to do this each time you are working on the project.

Run npm install -g mocha to install Mocha globally (this allows you to run Mocha from any directory on your computer).

Testing

Run mocha within the project directory to run all of the tests in the project.