Don't use /tmp as the path for temp files in the tests
In several tests, we use "/tmp" as the temp directory where we create files used for the tests. However, this seems to cause a problem on OSX when I run the tests locally, after Gitlab CI has run. The files exist and I can't supersede them because the owner/group is not me. I can't even remove the files with rm -f
using my account instead of the gitlab CI account.
We should probably use a temp directory in (or near) the "tests" directory so that we're isolated from such things.
It's probably better if Gitlab CI (on OSX) didn't do that, but that's apparently how it works and it's pretty finicky to get a new Gitlab runner set up, so this is a workaround for this problem.