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.
In Javascript you can't actually mark methods as private like you can in Ruby et al. BUT, sometimes you still want to distinguish between a class's public API and its private internal helper methods and junk. Hence the sad `// private` comment.