Disable local tcp test for gevent

src/python/grpcio_tests/commands.py

@@ -155,6 +155,8 @@ class TestGevent(setuptools.Command):
         'channelz._channelz_servicer_test.ChannelzServicerTest.test_streaming_rpc',
         # TODO(https://github.com/grpc/grpc/issues/15411) enable this test
         'unit._cython._channel_test.ChannelTest.test_negative_deadline_connectivity'
+        # TODO(https://github.com/grpc/grpc/issues/15411) enable this test
+        'unit._local_credentials_test.LocalCredentialsTest.test_local_tcp',
     )
     BANNED_WINDOWS_TESTS = (
         # TODO(https://github.com/grpc/grpc/pull/15411) enable this test