------------------
.. note::
This is really just a maintenance release, but changes a few deep things in
the development process. It also marks a *possible* fork point for dropping
Python 2 support.
* ``pyisbn`` errors are now children of ``PyisbnError``
* pytest_ is now required to run the tests
* expecter_ is no longer required
* 3.7 is now officially supported
.. _pytest: http://pytest.org/
.. _expecter: https://pypi.org/project/expecter/