- add support for UPDATE_USER_ON_LOGIN flag
- match version requirements in pyproject.toml to those in requirements/stable-psa.txt
- standardize usage of python3 in Makefile
- version bumps
- add property for URL
- add class variables for PATH, AUTHORIZATION_ENDPOINT, TOKEN_ENDPOINT, USERINFO_ENDPOINT
- switch to urllib.parse urljoin()
- add a Makefile