Do not mention gevent.six in changelog, it's not part of public interface and...

Do not mention gevent.six in changelog, it's not part of public interface and might be removed in the future

changelog.rst

@@ -25,7 +25,6 @@ Release highlights:
   - GEVENT_THREADPOOL allows choosing thread pool class.
 - Added new examples: portforwarder, psycopg2_pool.py, threadpool.py, udp_server.py
 - Fixed non-embedding build. To build against system libev, remove or rename 'libev' directory. To build against system c-ares, remove or rename 'c-ares'. Thanks to Örjan Persson.
-- Added gevent.six module (http://pypi.python.org/pypi/six)
 
 misc:
 - gevent.joinall() method now accepts optional 'count' keyword.