Killpack/auth *WIP* *WIP* *WIP*

WIP.

It's gonna work like this:
- You type in your username and password, which hits the `authorizations` endpoint. On successful authentication, it returns your auth token.
- Ember stores this auth token somewhere and uses it to make requests from thereon out.
Since we're overriding the `init` function, we need to make sure that the superclass's `init` function gets called, too, so that we don't accidentally wipe out any important initialization the superclass needs to do. `this._super()` is calling `Ember.Controller.init()`.