Update changelog.

Author: ionelmc

CHANGELOG.rst

@@ -8,6 +8,7 @@ Changelog
 * Allowed Manhole to be configured without any thread or activation (in case you want to manually activate).
 * Added an example and tests for using Manhole with uWSGi.
 * Fixed error handling in ``manhole-cli`` on Python 3 (exc vars don't leak anymore).
+* Fixed support for running in gevent/eventlet-using apps on Python 3 (now that they support Python 3).
 * Allowed reinstalling the manhole (in non-``strict`` mode). Previous install is undone.
 
 1.2.0 (2015-07-06)