:require_no_authentication for "edit" method doesn't allow the sign out code to be executed

[rubengut]

When accepting an invitation, edit method in Invitations Controller has code to sign out a user/resource if one is already signed in.
See:
https://github.com/scambra/devise_invitable/blob/master/app/controllers/devise/invitations_controller.rb#L40

This is something I needed in my project and tried to add myself overriding the edit method in the Invitations Controller. But I noticed my method wasn't even being called. It was because of the before filter require_no_authentication. Then I noticed the original edit code already had the code I needed, but it was just not being executed.

I ended up overriding the controller with only this line:

prepend_before_action :require_no_authentication, :only => [:update, :destroy]

[scambra]

I have removed that line, because it didn't work, now you may use in your controller this line:
prepend_before_action :sign_out, only: :edit

[scambra]

See #701