message: Enable api compatibility test to also run on macos.
diff: @@ -248,8 +248,8 @@ class ApiCompatibilityTest(test.TestCase):
  logging.info('No differences found between API and golden.')
  @unittest.skipUnless(
  - sys.version_info.major == 2 and os.uname()[0] == 'Linux',
  - 'API compabitility test goldens are generated using python2 on Linux.')
  + sys.version_info.major == 2,
  + 'API compabitility test goldens are generated using python2.')
  def testAPIBackwardsCompatibility(self):
  # Extract all API stuff.
  visitor = python_object_to_proto_visitor.PythonObjectToProtoVisitor()
  