Improved the quality as recommended by Sensio

See https://insight.sensiolabs.com/projects/aa05004d-c371-450a-bb45-4cc3dff8113a

* The `AuthController::authAction` method should not be too long (major, architecture)
* User specific files does not appear in .gitignore (minor, codestyle)
* Unused use statement should be avoided (minor, deadcode)