Add support for installing multiple packs at once to "st2-pack-install" CLI script.
Add support for installing multiple packs at once to "st2-pack-install"
CLI script.

nzlosh/st2,nzlosh/st2,StackStorm/st2,nzlosh/st2,Plexxi/st2,Plexxi/st2,StackStorm/st2,Plexxi/st2,StackStorm/st2,StackStorm/st2,nzlosh/st2,Plexxi/st2