CORD-433 Add virtual fabric to CiaB

Change-Id: I8fbea8c85f309a4c226951e0cde96a9b7394d6eb
diff --git a/ansible/group_vars/all b/ansible/group_vars/all
index 5c59599..24935cc 100644
--- a/ansible/group_vars/all
+++ b/ansible/group_vars/all
@@ -7,3 +7,4 @@
 debian_version: trusty
 docker_cfg: docker.cfg
 docker_cfg_dest: /etc/default/docker
+fabric: false