Update st2-self-check so it prints out output of st2 run on test failure.
Update st2-self-check so it prints out output of st2 run on test
failure.

Without doing that it's impossible to debug some test failures which are
due to action not taking all the parameters or similar.

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