Collapse job search

this adds the ability to handle collapsed job searches to the ruby api gem.  If collapse is off it will handle everything as it used to. But if collapse is on, it will go down the collapsed path and return a Cb::Models::CollapsedJobResults insted of a Cb::Models::JobResults
I talked and it was deemed best to use the existing api call on the gem since in reality they are the same API.  To my understanding the gem is supposed to represent the API, and if we want it to look different we can put an adapter in the way.