ok, so we can't use transactions for deletion because of octopus, so
we'd like to use deletion, which is fast. truncation is super slow.
unfortunately, mysql gives an error when trying to delete from a bunch
of tables in one command, per this:
https://github.com/bmabey/database_cleaner/issues/192
so i've forked this and have it just deleting with multiple commands,
which is way faster than truncation.