Improve and fix tests (#36)

* Parameterize test images.

* Use different images, similar to ansible/ansible#72698.

tests/integration/targets/docker_stack_info/tasks/test_stack_info.yml

@@ -31,8 +31,8 @@
         - 'output.results | type_debug == "list"'
         - 'output.results | length == 0'
 
-  - name: Copy compose files
-    copy:
+  - name: Template compose files
+    template:
       src: "{{ item }}"
       dest: "{{ output_dir }}/"
     with_items: