Handle timezone-aware timestamps (#810)

Handle timezone-aware timestamps

Since version 2.1.0, timestamps in PyGithub are timezone-aware.
Remove tzinfo in tests for easy comparison.
Related to packit/requre#275.

Reviewed-by: František Lachman <flachman@redhat.com>

tests/integration/github/test_generic_commands.py

@@ -190,10 +190,10 @@ def test_get_commit_statuses(self):
         assert last_flag.state == CommitStatus.success
         assert last_flag.context == "test"
         assert last_flag.uid
-        assert last_flag.created == datetime(
+        assert last_flag.created.replace(tzinfo=None) == datetime(
             year=2019, month=9, day=19, hour=12, minute=21, second=6
         )
-        assert last_flag.edited == datetime(
+        assert last_flag.edited.replace(tzinfo=None) == datetime(
             year=2019, month=9, day=19, hour=12, minute=21, second=6
         )