Fix py37

tests/rest/client/test_login.py

@@ -13,11 +13,12 @@
 # limitations under the License.
 import time
 import urllib.parse
-from typing import Any, Collection, Dict, List, Literal, Optional, Tuple, Union
+from typing import Any, Collection, Dict, List, Optional, Tuple, Union
 from unittest.mock import Mock
 from urllib.parse import urlencode
 
 import pymacaroons
+from typing_extensions import Literal
 
 from twisted.test.proto_helpers import MemoryReactor
 from twisted.web.resource import Resource