Leverage Amber routing for authenticated paths

[drujensen]

Description of the Change

This replaces the Authenticate pipe to remove the list of paths in the middleware with a new pipeline that will require authentication. This includes a second pipeline to load the CurrentUser in both the :web and new :auth routes.

To authenticate your routes, add them to the :auth pipeline instead of the :web pipeline.

This also removes the RegistrationController in favor of using the new and create restful methods in the UserController.

This also cleans up the UserController to match our other controllers closer.

Alternate Designs

Keep it as is.

Benefits

Take advantage of Ambers routing for authenticated paths

Possible Drawbacks

None I can think of

[drujensen]

@eliasjpr @elorest @robacarp @marksiemers Can you review? This removes the array of paths from the middleware that require authentication and uses an auth pipeline/routes instead.

[drujensen]

Thanks @robacarp