integration: Use vars_files in plays

It's unsightly and hard to maintain collections of references and long
lists across multiple playbooks/include files.  Centralize them all
in ``vars.yml``, then include that in all plays.

Minor: Update all files with a newline at the start and end.

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

contrib/test/integration/build/runc.yml

@@ -1,4 +1,5 @@
 ---
+
 - name: clone runc source repo
   git:
     repo: "https://github.com/opencontainers/runc.git"
@@ -18,4 +19,4 @@
   file:
     src: /usr/local/sbin/runc
     dest: /usr/bin/runc
-    state: link
+    state: link