add tag 'utilities' and change display name
stable release.
added testing using jest and the Firebase Emulator Suite.
feature - Added backfill capabilities so that we can have existing documents in the Firestore collection be checked for field uniqueness.
Added the require auth parameter upon installation, so developers can decide wether or not to check this function to be invoked only by authenticated users.
Removed the collection and fieldName parameters upon installation, and included them as parameters of the callable function.
Initial release of the Field Uniqueness HTTP extension.