title: Couple Firebase Firestore and Firebase Storage calls together into a batch?
body: <p>I'm looking for a best practice on combined/batch calls for Firebase Storage and Firebase Firestore. For example: I need to delete a document from my Firestore which is related to an image in Firebase Storage. 
  Is there a possibility to do this in such a way that when one of the actions fails, the whole transaction is being reverted?</p>