Latest version of filelock breaks CI

[gvegayon]

It seems that the latest version of filelock (which was updated ~20 mins ago since this post) is buggy. The CI of #158 fails as well as running other CIs that were previously working. Filelock went from 3.14.0 to 3.15.0. Here is the CI run that worked OK:

Here is the one that is not working:

I suggest forcing the old version (for now) so that we can continue developing without issues.

cc @gaborbernat

[gvegayon]

Also reported here

[damonbayer]

Most recent version was yanked. Should be fixed soon automatically, but I also made a PR #182