Add webserver in octavia/devstack/samples

Needs to add this file so vagrant script can run.

Change-Id: Iba28a75a9ba201d2a22594d9cb8ab7d4014360f7

devstack/samples/webserver.sh

@@ -0,0 +1,6 @@
+#!/bin/ash
+
+MYIP=$(/sbin/ifconfig eth0|grep 'inet addr'|awk -F: '{print $2}'| awk '{print $1}');
+while true; do
+    echo -e "HTTP/1.0 200 OK\r\n\r\nWelcome to $MYIP" | sudo nc -l -p 80
+done