message: Fix export_test failure
diff: @@ -358,7 +358,8 @@ class ExportTest(test_util.TensorFlowTestCase):
  with self.assertRaises(ValueError) as e:
  export.build_all_signature_defs(receiver_tensor, None)
  - self.assertEqual("export_outputs must be a dict.", str(e.exception))
  + self.assertTrue(str(e.exception).startswith(
  + "export_outputs must be a dict"))
  def test_get_timestamped_export_dir(self):
  export_dir_base = tempfile.mkdtemp() + "export/"
  