Added removable ship it labels such that a ship it label can be revoked only by the person who endorsed it in the first place. To revoke a ship it, click

on the X to the right of a ship it label. Ship its can be revoked and the changes seen immediately. Furthermore, the ship-it counter corrresponding to the review request is duly updated(decremented) when a ship it is revoked.

Manual testing using different users and reviews, and checking if appropriate permissions are met. 

Manual tests for ship its being revoked on click, and asynchronously. Furthermore, any checks to see if 

review request is up to date returns true. 

Unit tests for if ship it counter is being updated appropriately.