Forked repo and updated accordingly.

Hi! Just wanted to let you and anybody reviewing this know that we have forked this repo and made the necessary adjustments to get it working properly in the latest version of WordPress/GravityForms.

We will maintain this separately from here on under https://github.com/angelleye/gravity-forms-braintree

We are waiting for WordPress to approve our plugin submission there, and then it will be available on the WordPress plugin directory.