19.3.0
Prepare 19.3.0
Rename _version.py into _version_info.py
Update closure cell rewriting to use CodeType.replace() on 3.8 (#562)
Move package into src directory
Add default_role for Sphinx. (#571)
Fix default values that are not comparable with '==' (#586)
Use an overload to get better type checking on default_if_none (#418)
Add missing PythonTooOldError to stubs
Fixes generics in mypy types (#443)
Add PEP484 stubs (#238)
Fix some typing issues (#581)