Travis is failing for CSS testsuite pull requests?

Hi there,

I created a few pull requests for the CSS testsuite (and am working on
more), but it looks like Travis is failing with:

python: can't open file
'/home/travis/build/w3c/csswg-test/tools/travis/../../tools/build.py':
[Errno 2] No such file or directory

What's up with that? Example:
https://travis-ci.org/w3c/csswg-test/builds/81702698

Thanks,
-Christian