Don't build travis-ci off master or release
Don't build travis-ci off master or release

Release is merged straight off master, and master is tested on our
internal CI.

alphagov/whitehall,hotvulcan/whitehall,robinwhittleton/whitehall,YOTOV-LIMITED/whitehall,ggoral/whitehall,alphagov/whitehall,askl56/whitehall,robinwhittleton/whitehall,ggoral/whitehall,askl56/whitehall,ggoral/whitehall,hotvulcan/whitehall,askl56/whitehall,alphagov/whitehall,YOTOV-LIMITED/whitehall,ggoral/whitehall,robinwhittleton/whitehall,YOTOV-LIMITED/whitehall,alphagov/whitehall,YOTOV-LIMITED/whitehall,hotvulcan/whitehall,robinwhittleton/whitehall,hotvulcan/whitehall,askl56/whitehall