Allow expired app specific tokens to be deleted

data/model/appspecifictoken.py

@@ -39,6 +39,17 @@ def revoke_token(token):
   token.delete_instance()
 
 
+def revoke_token_by_uuid(uuid, owner):
+  """ Revokes an app specific token by deleting it. """
+  try:
+    token = AppSpecificAuthToken.get(uuid=uuid, user=owner)
+  except AppSpecificAuthToken.DoesNotExist:
+    return None
+
+  revoke_token(token)
+  return token
+
+
 def get_expiring_tokens(user, soon):
   """ Returns all tokens owned by the given user that will be expiring "soon", where soon is defined
       by the soon parameter (a timedelta from now).