Devise token auth not found routing error

[ghost]

My application is sending emails to confirm the new registration.

The client received that email and click the link. The account is confirmed and the client can sign in.
But if the user press again that link, he receives a routing error:

confirmations_controller.rb - line 29.

When the confirmation token is not found, we should get a proper message instead of a routing error.

The same is happening with password recover.

[ghost]

I created my own method to recover from errors when a 404 is raised from: api/v1/auth/confirmation/. In this way I can provide a nice error to the user.
Related with the edit password, I wasn't succeed because it is returning a 404 json.
I'm not so good in Rails. Another suggestions are welcomed.

I'm using devise_token-auth with ng-token-auth.

[ghost]

The following pull request:
Semantic Registrations Error Status Codes
#376

Solve the problem with registration link. The password link remain with problem when you click it for the second time.