adds test for user finder
Adds users controller logic
* adds user controller and its tests
* adds token mailer and its tests
* adds mailing config
Implements the logout feature
* adds more UsersController test
Adds support files for Heroku deployment
* adds unicorn server config file
* adds Procfile
* adds env vars for mailing config
Secured posts using current_user
* refactored some users routes
* fixed integration tests