def ref_data
      r = request(:get, '/WebObjects/iTunesConnect.woa/ra/apps/version/ref')
      data = parse_response(r, 'data')
      Spaceship::Tunes::AppVersionRef.factory(data)
    end
def ref_data
      r = request(:get, '/WebObjects/iTunesConnect.woa/ra/apps/version/ref')
      data = parse_response(r, 'data')
      Spaceship::Tunes::AppVersionRef.factory(data)
    end
Fetches the App Version Reference information from ITC
 @return [AppVersionRef] the response