If NODE_NAME env is not set, fall back to hostname.
Partial fix towards #23 we still have issue where kube-router is run as agent
and kubelet is started with --hostname-overide flag
by host name or FQDN. kubelet can be started with --hostname-override with configurable value.
In AWS envirinment typcally its set FQDN obtained from the metda data. This fix ensures
we can deploy kube-router in case nodes are registered with FQDN
Fixes#17