Some changes to the imgur module to make it more robust.

* Now handles various errors, like not 200 status responses and invalid json.
* Added an includeNSFW member var that can be changed to allow or dissalow nswf. Might want to to be an option somewhere else.
Enabled imgur tests for nsfw flag and non-200 responses.
Merge branch 'master' into imgurModule
Merge pull request #82 from HackThis/imgurModule

Imgur module improvements