add a `shell` alias by default
add a `shell` alias by default

Closes #1586

Signed-off-by: Tycho Andersen <10c18fcb898ee6b17d6575d444b125d10b3f4d6a@canonical.com>

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