asserting status code before decoding json in assertResponseNoErrors 

On a 404 with debug set to True the json decode will fail. `self.assertEqual(resp.status_code, 200)` should come before `json.loads(resp.content)`.

```
    def assertResponseNoErrors(self, resp):
        content = json.loads(resp.content)
        self.assertEqual(resp.status_code, 200)
        self.assertNotIn("errors", list(content.keys()))
```