From 2.0[0] onwards, all `ansible_ssh_*` variables are deprecated.

[0]: https://docs.ansible.com/ansible/2.3/intro_inventory.html

This has multiple benefits:
- We don't have to wait until Ansible 2.8 (which will be when the official hcloud dynamic inventory provider will be included)
- We can expand the script to group servers by labels if required
- We can use the vault to automatically get the hetzner cloud token which is not possible otherwise