Augment labels

When fetching a PR's labels on github, sometimes the existing labels are just strings, but other times they're the full on label dict with url, color, and name defined. Here's some log capture:

```
2014-10-14T22:36:29.711074+00:00 app[web.1]: PR 5561 does not have label needs triage to remove
2014-10-14T22:36:29.711084+00:00 app[web.1]: PR 5561 only has labels 
[{u'name': u'needs triage', u'color': u'e11d21', u'url': u'https://api.github.com/repos/edx/edx-platform/labels/needs+triage'}, u'community manager review']
```

so I'm adding in both types of labels so we can check if EITHER of them exist. I'm unclear why Github does this.