build the xos-base image and push to local repo

Change-Id: Ic606e9d8a04e9671ddfe3cf97a2dcb532c813b64
diff --git a/cord-head-playbook.yml b/cord-head-playbook.yml
index ce55372..8a821cf 100644
--- a/cord-head-playbook.yml
+++ b/cord-head-playbook.yml
@@ -42,6 +42,11 @@
     - { role: config-virt, become: yes }
     - create-vms
 
+- name: Create docker images
+  hosts: head
+  roles:
+    - xos-build
+
 - name: Set up VM's, juju, start ONOS and XOS
   hosts: head
   roles: