Add a test case which verifies we allow arbitrary properties inside pack.yaml file for future compatibility reasons.
Add a test case which verifies we allow arbitrary properties inside
pack.yaml file for future compatibility reasons.

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