use ruby 2.1.1 on travis
use ruby 2.1.1 on travis

rstacruz/bullet,sho-h/brakefast,theass/bullet,hannahbot/bullet,yakovenkodenis/bullet,rstacruz/bullet,theass/bullet,dwb/bullet,sho-h/brakefast,jay3126/bullet,flyerhzm/bullet,danp60/bullet,danp60/bullet,yakovenkodenis/bullet,rrosenblum/bullet,flyerhzm/bullet,jay3126/bullet,dwb/bullet,PikachuEXE/bullet,hannahbot/bullet,sideci-sample/sideci-sample-bullet,rrosenblum/bullet,PikachuEXE/bullet,eileencodes/bullet,flyerhzm/bullet,sideci-sample/sideci-sample-bullet,eileencodes/bullet