Cleanup sessions controller - webapp logs in through the api.

So the #create and #update actions were not needed anymore. Also removed the tests
remove email aliases controller - we don't use it anymore
use the login logout named route instead of sessions resource

The main part of the sessions resource now lives in the API. the two named routes are just fine for what is left.
clearify usage of V1::UsersController#index for autocomplete

[skip ci]
Merge pull request #79 from azul/cleanup/remove-outdated-controller-actions

Cleanup/remove outdated controller actions