omniauth + Google OAuth2 on Rails

Update 2013-03-10: modified to use figaro instead of rather half-baked parseconfig approach. Update 2013-03-24: modified to use ActiveRecord sessions and first_or_initialize for user creation (moving the logic from the model to the controller) All of the code for the following example is on GitHub. However for the sake of readability I have left out the init of a git repository in the description