Support for brand _link when showing articles

I'm not quite sure if this is the best way to handle this, but I found that I was unable to fetch the brand from the _link array when calling `ShowArticle`.

I traced the problem to the fact that Desk returns an array, and that we only expect objects: http://dev.desk.com/API/articles/#show (See "Example Response with Branding")

The code below gets the job done but feels hacky. Do you see a better way to do this? As far as I can tell, this is the only time when Desk returns an array in _links.