* Fix - Add phpunit-polyfills to test suite to comply with new wp test requirements
* Fix - Validate shipping values for ls payload
* Fix - Delete cache lock after product sync to be compatible with persistent caching
* New - Add sales syncing feature (beta)
* Fix - Images causing error when attempting to insert after store duplication. #309 - checks the image_id in thewclsi_item_images table first
* Tweak - Tags syncing should be a selectable option #304 - tags can now be turned on/off
* Fix - Remove "Uncategorised" too #302 - removes "Uncategorised"
* Fix - Images causing error when attempting to insert after store duplication. #309 - Orphaned images can now be updated properly
* Fix - Variation gallery images do not sync correctly #305 - Variation images are now properly stored in variation gallery post meta
* Fix - Wordpress times out when downloading lots or large images #303 - Wordpress times out on large image downloads, will now provide an error and abort product creation