Gravity Forms Stripe Addon 5.6.0

- Added support to deactivate Stripe feeds when the Stripe Card field is deleted.

- Updated webhook event logging statement to include the webhook API version.
- Fixed Stripe Elements not rendering for forms embedded in front-end pages.
- Fixed the credit card field button not being displayed in the form editor for existing installs.

- Added support for Stripe Checkout.
- Added support for Stripe Credit Card (Stripe Elements).
- Added support for the "charge.expired" event; changing the entry payment status from Authorized to Voided when an authorization expires.
- Added the "gform_stripe_entry_not_found_status_code" filter enabling the status code to be overridden.
- Reverted the callback error 'entry_not_found' to return a header status code of 200.
- Fixed processing of "invoice.payment_succeeded" and "invoice.payment_failed" events with Stripe API version 2018-05-21.
- Fixed a refund transaction being recorded in the sales tab when an authorized charge is manually released via the Stripe.com dashboard.
- Fixed plan creation with Stripe API version 2018-05-21.
- Fixed trials for new subscriptions with Stripe API version 2018-05-21.