message: Fix tests for python 3.7
  python 3.7 removes re._pattern_type. Fix the one place where we were
  depending on the type of regular expressions to compute the type
  dynamically.
diff: @@ -74,13 +74,14 @@ def _check_expected_version(comparison, expected, actual):
  LooseVersion(expected_str))
  +_re_pattern_type = type(re.compile(''))
  def _match_decorator_property(expected, actual):
  if actual is None or expected is None:
  return True
  if isinstance(expected, no_match):
  return not _match_decorator_property(expected.item, actual)
  - elif isinstance(expected, (re._pattern_type,) + six.string_types):
  + elif isinstance(expected, (_re_pattern_type,) + six.string_types):
  return re.search(expected, actual) is not None
  elif hasattr(expected, "__iter__"):
  return any([x is not None and _match_decorator_property(x, actual)
  