* Add support for Python 3.10 and 3.11.
* Drop support for Python 3.5 (EOL).
* Use ``CompoundFixture`` from ``fixtures>=2.0`` rather than
rolling our own.
* Make ``TestCase`` hashable.
* Prevent ``AttributeError`` in ``TestCase.__eq__`` for objects
lacking a ``__dict__`` attribute.
* Replace deprecated ``cgi`` module usage with ``email``.
OBS-URL: https://build.opensuse.org/package/show/devel:languages:python/python-testtools?expand=0&rev=77