title: Determine velocity coverage in a Python project
body: <p>Is there a way to determine the % test coverage for new code(as in code added/edited in a new commit) , and fail the tests if it falls below a threshold? This is different from just having a --cov-fail-under attribute in your setup.cfg as this checks your entire codebase and not just new code. The idea is to have 95% code coverage restriction on new code, even though right now our overall code coverage is 40%.</p>