==================
- Drop support for Python 3.4.
- Add support for Python 3.8 and 3.9.
- Fix accessing ``__parent__`` when it is defined as a class attribute
that is ``None`` (e.g., in subclasses of
``zope.conatiner.contained.Contained``). See `issue 24
<https://github.com/zopefoundation/ExtensionClass/issues/24>`_.