Tar-ball now has underscore like the wheel

Something changed in the pip/setuptools/wheel ecosystem.

.github/workflows/test.yml

@@ -36,6 +36,6 @@ jobs:
       run: |
         # Unpack the tests from the sdist tar-ball
         # (want to confirm the manifest was complete)
-        tar -zxvf dist/flake8-black-*.tar.gz
+        tar -zxvf dist/flake8_black-*.tar.gz
         cd flake8-black-*/tests/
         WIN="$([ "$RUNNER_OS" == "Windows" ];echo $?)" bash ./run_tests.sh