Add example/echo_client.py test into test/test_endtoend.py
Add example/echo_client.py test into test/test_endtoend.py

git-svn-id: a751b5b3dcfba0ee4592a85c40d2fdd063ca0d53@507 4ff78f4a-9131-11de-b045-6380ec9940d4

XiaonuoGantan/pywebsocket,XiaonuoGantan/pywebsocket