Add propertyNames to Draft6 patternProperties, do not skip patternProperties test

Author: manycoding

jsonschema/schemas/draft6.json

@@ -115,6 +115,7 @@
         "patternProperties": {
             "type": "object",
             "additionalProperties": { "$ref": "#" },
+            "propertyNames": { "format": "regex" },
             "default": {}
         },
         "dependencies": {

jsonschema/tests/test_validators.py

@@ -892,8 +892,6 @@ def test_invalid_pattern(self):
         with self.assertRaises(SchemaError):
             self.Validator.check_schema({"pattern": "\q"})
 
-    @unittest.skip("This test fails but it shouldn't, see"
-                   "github.com/Julian/jsonschema/pull/425#issuecomment-425667814")
     def test_invalid_patternProperty(self):
         with self.assertRaises(SchemaError):
             self.Validator.check_schema(