I'm beginning to realise why I didn't do the `toString` overriding way
back when. Thankfully, now that all of our tests are in the same place,
this is actually not a terrible ordeal.
These were causing `git` to behave strangely, leaving files that were
impossible to reset. In the future we should probably generate these
problematic test files on the fly, so that they don't have to exist in
the repo, but in the short run, it's easier to just remove them so as to
not block other users of the repo.
