When I test sdist from PyPI it always fails: ``` ImportError while loading conftest '$(BUILDDIR)/test/conftest.py'. test/conftest.py:11: in <module> os.path.join(TEST_DATA_DIR, p) for p in os.listdir(TEST_DATA_DIR) E FileNotFoundError: [Errno 2] No such file or directory: '$(BUILDDIR)/libbrotli/tests/testdata' ``` Apparently, the required directory is not in the sdist. Please add it there. Please also consider to add `tox.ini` to sdist. Thank you.