Create Artist Model

see http://www.songkick.com/developer/events-details
Add artist to JIPEvent and fake event objects in UpcomingConcertsVC
ConcertDetailsVC TableView get 2 AccessoryDetailDisclosureButton for Artist and Venue
Implement <TableViewDelegate> in ConcertDetailsVC to be able to push to VenueVC and ArtistVC
Create ArtistDetailsVC and Push it from ConcertDetailsVC