Add V3 API Test to get the VNC console of server

This patch adds V3 API Test to get the VNC console of server

Change-Id: I120163d0821eb7d8b2d62000be7cdd991925c341
diff --git a/tempest/config.py b/tempest/config.py
index 05a493c..89be5e5 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -263,7 +263,11 @@
     cfg.BoolOpt('block_migrate_cinder_iscsi',
                 default=False,
                 help="Does the test environment block migration support "
-                     "cinder iSCSI volumes")
+                     "cinder iSCSI volumes"),
+    cfg.BoolOpt('vnc_console',
+                default=False,
+                help='Enable VNC console. This configuration value should '
+                     'be same as [nova.vnc]->vnc_enabled in nova.conf')
 ]