Only two failing test now

```
  1) Error:
ConfirmationTest#test_user_with_valid_confirmation_token_where_the_token_has_expired_and_with_application_router_name_set_to_a_different_engine_and_route_overrides_back_to_main_it_shows_the_path:
NoMethodError: undefined method `user_on_main_app_confirmation_path' for #<ConfirmationTest:0x0000010b8c4428>
    actionpack (4.1.1) lib/action_dispatch/testing/assertions/routing.rb:171:in `method_missing'
    actionpack (4.1.1) lib/action_dispatch/testing/integration.rb:396:in `method_missing'
    /Users/andreasronge/projects/devise/test/integration/confirmable_test.rb:68:in `block (2 levels) in <class:ConfirmationTest>'
    /Users/andreasronge/projects/devise/test/support/helpers.rb:55:in `swap'

  2) Error:
ConfirmationTest#test_user_with_valid_confirmation_token_where_the_token_has_expired_with_router_overrides_different_engine_it_shows_the_path:
NoMethodError: undefined method `user_on_engine_confirmation_path' for #<ConfirmationTest:0x0000010654cc00>
    actionpack (4.1.1) lib/action_dispatch/testing/assertions/routing.rb:171:in `method_missing'

737 runs, 1933 assertions, 0 failures, 2 errors, 0 skips
```