Add tests to product page

This patch updates the product page to include tests
associated to versions of the product. This allows filtering
results based on a product_id. Tests associated with private
products will have their product information hidden.

Change-Id: Ic5b6b45c9e3d14d9c2cb36a8eba72f2a6e31d2aa

refstack/tests/unit/test_api.py

@@ -141,7 +141,7 @@ class ResultsControllerTestCase(BaseControllerTestCase):
         mock_get_test.assert_called_once_with(
             'fake_arg', allowed_keys=['id', 'cpid', 'created_at',
                                       'duration_seconds', 'meta',
-                                      'product_version_id',
+                                      'product_version',
                                       'verification_status']
         )
 
@@ -251,6 +251,7 @@ class ResultsControllerTestCase(BaseControllerTestCase):
             const.CPID,
             const.SIGNED,
             const.VERIFICATION_STATUS,
+            const.PRODUCT_ID
         ]
         page_number = 1
         total_pages_number = 10