Update file input builder to Bootstrap 3
Update file input builder to Bootstrap 3

Wrap generated markup in the `form-group` class

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