Standardize naming
Use stricter assertions and reduce boilerplate to make the intent of the tests more obvious.
Also explicitly sort the filenames so that the correct files are pruned,
and so that the tests can not flake.
The tests all run fast enough that we do not get any advantage from
using Parallel.
The one test that was slow used a long sleep. Changing the sleep to
a few milliseconds speeds up the test considerably.
Daniel Nephin