Fix brooklyn-dns-etc-hosts-generator going on-fire
Fix brooklyn-dns-etc-hosts-generator going on-fire

Previously, if a k8s worker or master went on-fire, and was being 
elegantly replaced by the cluster’s recovery policy, the group 
“brooklyn-dns-etc-hosts-generator” would still mark itself as on-fire
because it’s quorum was “all”. That would cause the whole app to mark 
itself as on-fire.
brooklyncentral/clocker,aledsage/clocker