Fix vagrant regression

Fixes #2475 

There were a number of issues:

1. The kube-apiserver cannot pick the first interface it finds to set the address to listen to for public interaction, it must be the address that corresponds to eth1, which is $MASTER_IP, which is routable in the private cluster.
2. The kubelet would never previously start because a prereq to the service.running clause was the presence of the kubernetes_auth file which was not present outside of GCE.
3. The minion grains.conf needed a set entry for the address to use to contact the readonly API server against because ips[0][0] could not be used since according to the current mine.conf, it looks for eth0 which does not exist as an interface name on the vagrant setup.

We should do a future PR to make the network interface to use not hard-coded to eth0, but this gets around the issue using the other enumerated flags which are far more deterministic right now.