Added pods stuff to gitignore.
Added pods stuff to gitignore.

iOSTestApps/xkcd-Open-Source,mamaral/xkcd-Open-Source,RyanCopley/xkcd-Open-Source,iOSTestApps/xkcd-Open-Source,mamaral/xkcd-Open-Source,RyanCopley/xkcd-Open-Source,RyanCopley/xkcd-Open-Source,IsaacChapman/xkcd-Open-Source,Suninus/xkcd-Open-Source,IsaacChapman/xkcd-Open-Source,mamaral/xkcd-Open-Source,IsaacChapman/xkcd-Open-Source,Suninus/xkcd-Open-Source,RyanCopley/xkcd-Open-Source