Login

In this PR
========
* Create Login controller to govern the session around login and logout. 
* Hook up Application controller to check the authentication every time.
* Created Auth Route (will be the parent of all routes that needs Auth to operate)
* Store the token and user info in the session
* Use localStorage for session data to persist between reloads
* Hook in `logout` call to server.
* Send back the token on all requests as part of the header.

Depending on https://github.com/CrazyHorseHQ/smart_app/pull/31
you can still manually go to `/login`, nothing to stop you. Would love to avoid double logins.