Add a smoke test script

[schu]

The script, for instance ./tests/smoke.sh, would

• do a clean kubeadm-nspawn Vagrant setup,
• use kubectl to verify the successful setup of k8s,
• do a deploy and
• query the deployed service to verify it's running.

[robertgzr]

To check k8s setup? kubectl -n kube-system get nodes

What can we deploy to test? https://github.com/kubernetes/kubernetes/tree/master/examples/https-nginx minus TLS?

[robertgzr]

Or maybe https://github.com/kubernetes/kubernetes/tree/master/examples/guestbook

[schu]

To check k8s setup?

Yes, a minimal script to test everything (that is expected to work) works as expected.