Add Ansible-lint CI step (#4411)

* Add ansible-lint as gitlab-ci step

* Fix jinja2 syntax in include_tasks that breaks ansible-lint

* Use a block scalar to get around gitlab quoting/escaping rules

* Run ansible-lint in verbose mode in CI

roles/download/tasks/main.yml

@@ -4,9 +4,10 @@
     - not skip_downloads|default(false)
 
 - name: "Download items"
-  include_tasks: "download_{% if download.container %}container{% else %}file{% endif %}.yml"
+  include_tasks: "{{ include_file }}"
   vars:
     download: "{{ download_defaults | combine(item.value) }}"
+    include_file: "download_{% if download.container %}container{% else %}file{% endif %}.yml"
   with_dict: "{{ downloads }}"
   when:
     - not skip_downloads|default(false)