------------------
- Do not require ``mock`` for the test suite on Python 3; use unittest.mock
instead.
- 100% test coverage for each version of Python rather than combined, using
``coverage-python-version``.
- Add the optional ``extra_node_attrs`` parameter to ``show_backrefs`` and
``show_backrefs``
- Fix IPython/Jupyter inline graph support code that would kick in even if you
explicitly passed a filename='foo.png' argument to
``show_refs``/``show_backrefs``. See `issue 47
<https://github.com/mgedmin/objgraph/issues/47>`_.
- Add support for Python 3.8.
- Drop support for Python 3.5.