Gravity Forms Constant Contact Add-On 1.8.0

- Updated the Custom Fields setting on the feed configuration page to use the generic_map type field instead of the deprecated dynamic_field_map type field.
- AF: Updated process_feed() return value for compatibility with Gravity Forms 2.9.4, so the framework can save the feed status to the entry meta.

- Updated to process feeds in the background to prevent API issues delaying submission completion.
- Updated to retry token refresh if the request fails before disconnecting.

- Fixed an issue connecting to new Constant Contact apps.
- Updated the connection method to prevent existing apps from breaking as of March 31, 2022