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.
The scope of "this" still confuses me. I would have guessed "this" would be "beforeModel", not (as assumed by line 7 below), "AuthenticatedRoute".