message: Enable Kafka test on macOS
  I think issue 131 likely should have be fixed by PR 192,
  so give it a try to enable Kafka on macOS.
diff: @@ -18,7 +18,6 @@ from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  -import sys
  import time
  import pytest
  @@ -32,9 +31,6 @@ from tensorflow.compat.v1 import data # pylint: disable=wrong-import-position
  import tensorflow_io.kafka as kafka_io # pylint: disable=wrong-import-position
  -if sys.platform == "darwin":
  - pytest.skip("kafka is failing on macOS", allow_module_level=True)
  -
  class KafkaDatasetTest(test.TestCase):
  """Tests for KafkaDataset."""
  