Authenticating users

[hchood]

Devise doesn't really work with rails-api. The instructions for ember-simple-auth-devise didn't work because warden uses the session, which isn't part of rails-api (and we don't want to enable sessions on the rails side).

https://github.com/simplabs/ember-simple-auth/tree/master/packages/ember-simple-auth-devise

Instead, using ember-simple-auth-oauth2:

https://github.com/simplabs/ember-simple-auth/tree/master/packages/ember-simple-auth-oauth2

Is that the best option?