Use jQuery inArray over indexOf for IE support
Use jQuery inArray over indexOf for IE support

IE 8 doesn't support indexOf on arrays. Using the jQuery inArray lets us
have a cross browser way of doing this.

https://www.pivotaltracker.com/story/show/52907471

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