Housekeeping

Some general cleanup. Goals:
* Have tests passing out of the gate (provide .env.test)
* Remove unneeded files/folders/gems/routes
* Upgrade Ruby (2.1.5), Rails (4.1.8)
* Make Gemfile more readable

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AC & CT
The goal is for iHat to keep running if Bugsnag is not present. Does the app continue to function if `BUGSNAG_API_KEY` is not set in the environment?