WooCommerce Google Analytics Pro 2.2.0

* Misc - Add support for WooCommerce 3.3
* Misc - Remove support for WooCommerce 2.5

* Tweak - Ensure "completed purchase" event is tracked even if Google Analytics Client ID cannot be determined at checkout

* Tweak - Ensure orders placed by customers are tracked even when manually set as paid by admins
* Fix - Ensure a tracking ID is set before outputting tracking scripts
* Dev - Fire an action after tracking code is set up
* Dev - Tracker options are now filterable
* Misc - Update SkyVerge Plugin Framework