I'm really keen on getting rid of the ckanclient dependency (#31) which is not used anywhere else on the code. Can you replace this with a direct call to the rest API?
eg:
```
url = harvest_object.source.url + self._get_rest_api_offset() + '/group/' + group_name
try:
    content = self._get_content(url)
except Exception,e:
    log.error('Could not get remote group %s' % group_name)
    continue
group = json.loads(content)
```

The rest of the code will work exactly as now.