WooCommerce Zapier Integration 2.13.0

* Full details: WooCommerce Zapier 2.2.2 Maintenance Release
* Change: WooCommerce Zapier now integrates with 3,800+ apps on Zapier.com. #499
* Change: Legacy Feed Migration deadline. PR #500
* Change: Marked as compatible with WooCommerce 5.8. #499

* Full details: WooCommerce Zapier 2.2 - WooCommerce Bookings Integration & More
* New: Added WooCommerce Bookings support. The minimum required WooCommerce Bookings version is 1.15.35. PR #413
* Change: Marked as compatible with WooCommerce 5.3. PR #

* Full details: WooCommerce Zapier 2.1 Released
* New: Add support for the newly released WooCommerce Subscriptions v3.1. #426, #431
* Fix: Avoid a PHP fatal error that occurs with WooCommerce Subscriptions v3.1 (which introduces a v3 subscriptions REST API endpoint). PR #425
* Fix: Ensure Subscriptions webhooks are created with the REST API v1 version, to improve compatibility with WooCommerce Subscriptions version 3.1. #431
* Fix: Performance Improvement: ensure resources are initialised only once (not twice). PR #411.
* Change: Remove unused REST API endpoint routes and methods. #412
* Change: Minimum required PHP version is now 7.0. No longer supporting PHP 5.6.x. #423
* Change: Minimum required WordPress version is 4.9.0. #423
* Change: Minimum required WooCommerce version is 3.7.0. #213, #423
* Change: Marked as compatible with WooCommerce 5.2. PR #417, PR #428
* Change: Update documentation links to new doc.om4.io site. PR #439
* Dev: Refactor resource definitions #422