Gravity Forms Stripe Addon 5.6.0

- Added security enhancements.
- Fixed a PHP fatal error which can occur if the customer specified by the gform_stripe_customer_id filter can't be retrieved.
- Fixed an issue where the Checkout session could fail to be created when the gform_stripe_customer_id filter returns a valid id and the customer email is supplied by the feed field mapping.
- Fixed an issue where PHP fatal error is thrown when Stripe account is deleting test data.

- Added license key to authorization url.
- Fixed a PHP fatal error which can occur if the customer specified by the gform_stripe_customer_id filter can't be retrieved.
- Fixed an issue where the Checkout session could fail to be created when the gform_stripe_customer_id filter returns a valid id and the customer email is supplied by the feed field mapping.

- Added security enhancements.