Fix pack action aliases base test class so it also works if directory name doesn't match pack name.
Fix pack action aliases base test class so it also works if directory
name doesn't match pack name.

We do that by inferring pack name from pack.yaml file. This way it works
with new pack management when local git repo directory name might not
match pack name.

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