nodeup: create kubeconfig under admin or root
nodeup: create kubeconfig under admin or root

While the admin account is created on stock debian images, it isn't on
all of them.  Check admin first, then check root, and don't treat it as
an error if neither is found - this is only a convenience.

mad01/kops,mad01/kops,andrewsykim/kops,chrislovecnm/kops,gambol99/kops,andrewsykim/kops,robinpercy/kops,gambol99/kops,robinpercy/kops,mad01/kops,blakebarnett/kops,justinsb/kops,blakebarnett/kops,tsupertramp/kops,robinpercy/kops,chrislovecnm/kops,gambol99/kops,kubernetes/kops,blakebarnett/kops,tsupertramp/kops,gambol99/kops,chrislovecnm/kops,chrislovecnm/kops,justinsb/kops,andrewsykim/kops,aledbf/kops,tsupertramp/kops,tsupertramp/kops,blakebarnett/kops,andrewsykim/kops,justinsb/kops,kubernetes/kops,aledbf/kops,mad01/kops,kubernetes/kops,aledbf/kops,robinpercy/kops,aledbf/kops