fixed bugs with mitaka

Change-Id: Ibb0eee5e842db30d348365812e9fb04077cd3b08
diff --git a/README.rst b/README.rst
index 405e43f..e56c428 100644
--- a/README.rst
+++ b/README.rst
@@ -15,6 +15,7 @@
         enabled: true
         identity: cloud1
         image_location: http://...
+        disk_format: qcow2
         public_network: INET1
 
     avinetworks: