* refactoring - symlinks to common/ directory
* inital SafeSpring terraform setup

* k8s
* helm
* calico
* prometheus
* grafana

* GPU node automatic creation through terraform
* update deploy script
* update playbooks
* enable NVidia GPU in the k8s cluster

Docker unmounts overlay2 directory when stopping. Post shutdown script
will remount it again.

Better to prefer inventory hostname for kube server. But for sites without public IPv4 we need to use local IPv4 instead. Use inventory host variable for the override.