Remove Tag on Cancel

[n7studios]

Summary

Adds this requested functionality to remove a tag when a MemberMouse Membership Level or Bundle is removed from a member.

Testing

• testMemberTagRemovedWhenBundleCancelled: Test that the subscriber's tag is removed in Kit when their MemberMouse bundle is cancelled.
• testMemberTagRemovedWhenMembershipLevelCancelled: Test that the subscriber's tag is removed in Kit when their MemberMouse membership level is cancelled.
• testMemberTagRemovedWhenDeleted: Test that the subscriber's tag is removed in Kit when their member account is deleted in MemberMouse.

Checklist

• I have written a test and included it in this PR
• I have run all tests and they pass
• The code passes when running the PHP CodeSniffer
• Code meets WordPress Coding Standards for PHP, HTML, CSS and JS
• Security and Sanitization requirements have been followed
• I have assigned a reviewer or two to review this PR (if you're not sure who to assign, we can do this step for you)