The auto-decorating metaclass was interfering with parameterized methods
on Python 2.7.  But we don't need it anymore anyway, since pytest will
let us hook to deal with the exception in a simpler way.

Another step toward removing unittest.TestCase.

Python 3.10 finally got super-noisy about load_module, which has been
deprecated since 3.4!

https://docs.python.org/3/library/importlib.html#importlib.abc.Loader.load_module

"DeprecationWarning: Use inspect.signature() instead of inspect.getfullargspec()"

This started appearing with Python 3.8a4.