Include playbook variables from file

This allows alternate playbooks to share the same variable definitions
as the primary crio-integration-playbook.  It remains possible to
override them via the command-line if needed.

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

contrib/test/crio-integration-playbook.yaml

@@ -2,9 +2,8 @@
 
 - hosts: all
   remote_user: root
-  vars:
-    xunit: false
-    cni_commit: dcf7368eeab15e2affc6256f0bb1e84dd46a34de
+  vars_files:
+    - crio-integration-vars.yaml
   pre_tasks:
     ## This playbook expects --extra-vars "commit=<commit>"
     ## and either --extra-vars "pullrequest=<PR #>" or
@@ -12,8 +11,8 @@
     - assert:
         that: 'commit is defined and commit | trim'
     - assert:
-      that: 'pullrequest is defined and pullrequest | trim'
-      tags:
-        - pr
+        that: 'pullrequest is defined and pullrequest | trim'
+        tags:
+          - pr
   roles:
     - integration_tests

contrib/test/crio-integration-vars.yaml

@@ -0,0 +1,4 @@
+---
+
+xunit: false
+cni_commit: dcf7368eeab15e2affc6256f0bb1e84dd46a34de