4.4.0:
- ``jupyter troubleshoot`` gets the list of packages from the Python environment
it's in, by using ``sys.executable`` to call ``pip list``.
- Added utility function ``ensure_dir_exists``, and switched to using it over
the one from ipython_genutils, which does permissions wrong.
- Avoid creating the ``~/.ipython`` directory when checking if it exists for
config migration.
- Fix mistaken description in zsh completions.
- Fix subcommand tests on Windows.
- The README now describes how to work on ``jupyter_core`` and build the docs
- Fix a broken link to a release in the docs