Add test for required property

Author: erayd

tests/Constraints/DefaultPropertiesTest.php

@@ -33,6 +33,11 @@ public function getValidTests()
                 '{"properties":{"propertyTwo":{"default":"valueTwo"}}}',
                 '{"propertyOne":"valueOne","propertyTwo":"valueTwo"}'
             ),
+            array(// fulfil required property with a default value
+                '{"propertyOne":"valueOne"}',
+                '{"properties":{"propertyTwo":{"required":true,"default":"valueTwo"}}}',
+                '{"propertyOne":"valueOne","propertyTwo":"valueTwo"}'
+            ),
             array(// default value for sub-property
                 '{"propertyOne":{}}',
                 '{"properties":{"propertyOne":{"properties":{"propertyTwo":{"default":"valueTwo"}}}}}',