Add oneshot states to prepare freshly cloned machines

hshbase/oneshot/README

+States in this directory are meant to be fired at a machine once if needed.
+Do NOT put them into your top.sls, or you will suffer.

hshbase/oneshot/after-clone-prep.sls

+include:
+  - .clear-systemd-machine-id
+  - .renew-openssh-keys
+

hshbase/oneshot/clear-systemd-machine-id.sls

+/etc/machine-id:
+  file.managed:
+    - mode: 0444
+    - contents: ''

hshbase/oneshot/renew-openssh-keys.sls

+hshbase_clear_old_ssh_host_keys:
+  cmd.run:
+    - name: 'bash -c "rm -v /etc/ssh/ssh_host_*key*'
+    - user: root
+
+hshbase_regenerate_ssh_host_keys:
+  cmd.run:
+    - name: 'dpkg-reconfigure openssh-server'
+    - user: root
+    - require:
+      - cmd: hshbase_clear_old_ssh_host_keys
+
+hshbase_restart_sshd:
+  cmd.run:
+    - name: 'systemctl restart ssh'
+    - user: root
+    - require:
+      - cmd: hshbase_regenerate_ssh_host_keys