Improve package-install speed for default config

The ``ansible.conf`` file has an option for ``squash_actions`` which
affects the package module.  It improves performance by bypassing the
normal ``with_items`` loop so all the items are installed at once.  This
vastly improves performance.

However (sadly) current origin-ci does not utilize the ``ansible.conf``
file in the repo.  Work around this by forming all required packages
into a CSV list.  Same effect, less magic, and it doesn't depend on any
``ansible.conf`` setting.

Signed-off-by: Chris Evich <cevich@redhat.com>

contrib/test/integration/system.yml

@@ -1,10 +1,8 @@
 ---
 
-- name: Make sure we have all required packages
-  package:
-    name: "{{ item }}"
-    state: present
-  with_items:
+- name: Required packages are buffered so package module can install all at once
+  set_fact:
+    required_packages:
         - container-selinux
         - curl
         - device-mapper-devel
@@ -54,6 +52,11 @@
         - socat
         - tar
         - wget
+
+- name: Make sure we have all required packages
+  package:
+    name: "{{ required_packages | join(', ') }}"
+    state: present
   async: 600
   poll: 10