Rails 4.1.0 update

This updates Rails to 4.1.0 (no Release Candidate) 

Adds ```sdoc``` for documentation generation. 

Also adds the following gems for a better development experience:
* ```better_errors```
* ```binding_of_caller```
* ```quiet_assets```

Also adds the following gems for access control:
* ```devise``` (Authentication)
* ```pundit``` (Authorization)