Update changelog

Author: rhpvorderman

CHANGELOG.rst

@@ -7,8 +7,10 @@ Changelog
 .. This document is user facing. Please word the changes in such a way
 .. that users understand how the changes affect the new version.
 
-version 0.3.1-dev
+version 0.4.0-dev
 -----------------
++ Move wheel building to cibuildwheel on github actions CI. Wheels are now
+  provided for Mac OS as well.
 + Make a tiny change in setup.py so python-isal can be build on Mac OS X.
 
 version 0.3.0