Fix python3 ReferenceError

README.md

@@ -1,3 +1,5 @@
+[![Build Status](https://travis-ci.org/invisibleroads/socketIO-client.svg?branch=master)](https://travis-ci.org/invisibleroads/socketIO-client)
+
 socketIO-client
 ===============
 Here is a [socket.io](http://socket.io) client library for Python.  You can use it to write test code for your socket.io server.

socketIO_client/__init__.py

@@ -289,7 +289,10 @@ class SocketIO(object):
         self.wait(seconds, for_callbacks=True)
 
     def disconnect(self, path=''):
-        self._transport.disconnect(path)
+        try:
+            self._transport.disconnect(path)
+        except ReferenceError:
+            pass
         try:
             namespace = self._namespace_by_path[path]
             namespace.on_disconnect()