Update Gem Dependencies

[webaholik]

These warnings are displayed when app is started:

app-1    | Top level ::CompositeIO is deprecated, require 'multipart/post' and use `Multipart::Post::CompositeReadIO` instead!
app-1    | Top level ::Parts is deprecated, require 'multipart/post' and use `Multipart::Post::Parts` instead!

I believe that the majority of these warnings are being generated by the current dependencies of the gcloud_storage gem. I'm not sure what all is involved, but based on my research so far, these are the basic changes needed to the dependencies:

# gcloud_storage.gemspec

-  spec.add_dependency             "google-cloud-storage", "1.15.0"
-  spec.add_dependency             "faraday", "0.15.4"
+  spec.add_dependency             "google-cloud-storage", "1.44.0"
+  spec.add_dependency             "faraday", "1.10.3"


-  spec.add_development_dependency "mime-types"
+  spec.add_development_dependency "mini_mime"

[webaholik]

@itsprdp @saichander - are you willing to take this task on? If it's something I can help with, I may raise a pull request, but before I do, I want to make sure that it can be merged and that the updated gem will be published

[itsprdp]

@webaholik please create the PR and I will try to review and merge it, thank you!