tests: Use shutdown and waitready commands
tests: Use shutdown and waitready commands

Signed-off-by: Stéphane Graber <089afc6d81f66f1168a9849e15660feae286e024@ubuntu.com>

dustinkirkland/lxd,yura-pakhuchiy/lxd,hallyn/lxd,techtonik/lxd,techtonik/lxd,Skarlso/lxd,mjeanson/lxd,lxc/lxd,georghopp/lxd,lxc/lxd,stgraber/lxd,chrisglass/lxd,georghopp/lxd,lxc/lxd,lxc/lxd,dustinkirkland/lxd,pcdummy/lxd,jsavikko/lxd,stgraber/lxd,Skarlso/lxd,pcdummy/lxd,erikmack/lxd,akshaykarle/lxd,pcdummy/lxd,mjeanson/lxd,ollie314/lxd,hallyn/lxd,jsavikko/lxd,hallyn/lxd,lxc/lxd,hallyn/lxd,lxc/lxd,chrisglass/lxd,hallyn/lxd,akshaykarle/lxd,Skarlso/lxd,stgraber/lxd,erikmack/lxd,erikmack/lxd,jsavikko/lxd,atxwebs/lxd,stgraber/lxd,akshaykarle/lxd,georghopp/lxd,atxwebs/lxd,chrisglass/lxd,dustinkirkland/lxd,stgraber/lxd,ollie314/lxd,atxwebs/lxd,hallyn/lxd,atxwebs/lxd,lxc/lxd,mjeanson/lxd,yura-pakhuchiy/lxd,techtonik/lxd,stgraber/lxd,Skarlso/lxd,yura-pakhuchiy/lxd,ollie314/lxd,stgraber/lxd