[firewall] Install python dependencies

roles/firewall/tasks/main.yml

 ---
+- name: Install firewall dependencies
+  apt:
+    update_cache: true
+    install_recommends: false
+    name:
+      - python3-iso8601
+      - python3-jinja2
+      - python3-ldap
+  register: apt_result
+  retries: 3
+  until: apt_result is succeeded
+
 - name: Create firewall directory
   file:
     path: /var/local/firewall