Add HA option, change to yaml inventory, cleanup

- HA option for multiple server nodes using embedded etcd
- Switch to yaml inventory file for easier editing and combining vars
- Update to full ansible module names
- Change master/node names to server/agent
- Cleanup small linting errors
- Add reboot playbook which staggers reboot to keep HA cluster up
- Move playbooks to playbook directory

Signed-off-by: Derek Nola <derek.nola@suse.com>