Remove unused and obsolete tasks from tox.ini.
Remove unused and obsolete tasks from tox.ini.

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