Allow customization of gce-setup.sh
Allow customization of gce-setup.sh

Allowing user to override VM name, so that gce-setup.sh could be used
from multiple machines at once.  Allowing zone to be overridden by
user,a nd if not, will use gcloud config to set zone. This supports
developers running from different locations.

Mirantis/kubeadm-dind-cluster