5.4.1:
Fix error in a newly added test.
Changed code format and quality checking infrastructure.
5.4.0:
Re-expose natsort_key as "public" and remove the associated DepricationWarning.
Add better developer documentation.
Refactor tests.
Bump allowed fastnumbers version.
5.3.1:
- No bugfixes or features, just infrastructure and installation updates.
- Move to defining dependencies with Pipfile.
- Development layout is now src/natsort/ instead of natsort/.
- Add bumpversion infrastructure.
- Extras can be installed by "[]" notation.
