Challenge #1 of 1

Simple centralization and removing duplication. Instead of having logic to redirect the user in the authenticator and in our controller, we can just return this value and remove the extra redirect logic in the controller.

This is needed so that we return the same response as the authenticator. Without this, the session cookie can't be sent back to the user.

If the user originally went to a page that required authentication (e.g. /checkout), then eventually went to the registration form and submitted it, this will redirect the user back to their original page (i.e. /checkout).