Fix incorrectly-named test suite function (#1116)

Closes #1102

Author: kurtmckee

tests/test_api_jwt.py

@@ -264,7 +264,7 @@ def test_decode_raises_exception_if_nbf_is_not_int(self, jwt):
         with pytest.raises(DecodeError):
             jwt.decode(example_jwt, "secret", algorithms=["HS256"])
 
-    def test_decode_raises_exception_if_aud_is_none(self, jwt):
+    def test_decode_allows_aud_to_be_none(self, jwt):
         # >>> jwt.encode({'aud': None}, 'secret')
         example_jwt = (
             "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9."