cleaner to compare to json

For future reference, you can break the string up into pieces to avoid
the long line.

documentcloud/documents/tests/test_views.py

@@ -57,10 +57,7 @@ def test_create_freestanding_entity(self, client, document, user, mocker):
         )
 
         assert response.status_code == status.HTTP_201_CREATED
-        assert (
-            response.content
-            == b'{"name":"Dog","kind":"unknown","metadata":{"wikipedia_url":"https://en.wikipedia.org/wiki/Dog"}}' # pylint: disable=line-too-long
-        )
+        assert response.json() == entity_body
         _get_or_create_entities.assert_called_once_with([entity_body])