I'm trying to make this iugu example work: link
I have a iugu account in test mode.
I followed the steps in this tutorial, I made the necessary modifications like putting my account id in the defined place and the api key in the controller. I am in testing mode and using the api key of tests. I am using the test credit card on 4111 1111 1111 1111. However the return of charge.success is always false and there is an error message.