test for RecommenderXBlock

It's *way* too hard to read what's going on here -- your indentation makes no sense. Try this, instead:
```python
url = self.get_handler_url('add_resource', xblock_name)
resp = self.client.post(url, json.dumps(resource), '')
return json.loads(resp.content)
```
Can you also explain what you're doing and why in the function docstring?