Fix post-create ping

vm.py

@@ -242,7 +242,7 @@ IP:         {0.ip}
 Username:   {0.user}
 Password:   {0.password}'''.format(instance))
 
-    subprocess.call(['ping', '-c', '1', '-W', '240', instance.ip])
+    subprocess.call(['ping', '-n', '-c', '1', '-w', '240', instance.ip])
 
 
 def cmd_iplist(args):