Enable invalid regex tests

Author: manycoding

jsonschema/tests/test_validators.py

@@ -1141,11 +1141,11 @@ def test_enum_allows_non_unique_items(self):
         self.Validator.check_schema({"enum": [12, 12]})
 
 
-class TestDraft6InvalidRegex(InvalidRegexMixin, object):
+class TestDraft6InvalidRegex(InvalidRegexMixin, TestCase):
     Validator = validators.Draft6Validator
 
 
-class TestDraft7InvalidRegex(InvalidRegexMixin, object):
+class TestDraft7InvalidRegex(InvalidRegexMixin, TestCase):
     Validator = validators.Draft7Validator