by expanding our test harness to be closer to how the tests get
run under pytest (which we don't support yet)

Also fix a couple minor things that this turned up.  There is a lot more
to be found here: the new harness supports many more of the sqlalchemy
tests, a number of which aren't working for us.  Also there is some
sort of issue with the current tests that we run, since repeating the tests
multiple times will end up crashing.