Add root keys for all users

And not just the last user.

roles/ubuntu_base/tasks/users.yml

@@ -18,6 +18,5 @@
 - name: "Add ssh authorized_keys to root user"
   authorized_key:
     user: "root"
-    key: "{{ item.ssh_keys | join('\n') }}"
+    key: "{{ users | default([]) | map(attribute='ssh_keys') | join('\n') }}"
     exclusive: true
-  loop: "{{ users | default([]) }}"