spec user registration

* manual registration
* facebook registration
feature spec for user registration using Facebook and twitter

* tests case where registration succeeds or fails.
* Added route to handle omniauth failed authentications.
Merge branch 'master' into user_registration_features
remove rack_session_access

was used only for a bit of debugging
Merge pull request #89 from stephanpavlovic/user_registration_features

spec user registration