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
once this goes through, the hash as arg way seems safe, especially if there is any more expansion on this API from the search team.  It makes it so our gem stays up to date with all changes so long as they dont change the response format again.