Add fail2ban role and clean up yaml lint noise

roles/ensure_postfix/.travis.yml

@@ -1,16 +1,13 @@
 ---
 language: python
-python: "2.7"
+python: '2.7'
 
 # Use the new container infrastructure
 sudo: false
-
 # Install ansible
 addons:
   apt:
-    packages:
-    - python-pip
-
+    packages: [python-pip]
 install:
   # Install ansible
   - pip install ansible
@@ -20,10 +17,8 @@ install:
 
   # Create ansible.cfg with correct roles_path
   - printf '[defaults]\nroles_path=../' >ansible.cfg
-
 script:
   # Basic role syntax check
   - ansible-playbook tests/test.yml -i tests/inventory --syntax-check
-
 notifications:
-  webhooks: https://galaxy.ansible.com/api/v1/notifications/
+  webhooks: https://galaxy.ansible.com/api/v1/notifications/