- Drop `Python < 3.8` and `Django < 2.2` support. 99
- Add backend for using default static storage (`"maintenance_mode.backends.StaticStorageBackend"`). (by [matmair](https://github.com/matmair) in #97)
- Replace `str.format` with `f-strings`.
- Replace `setup.py test` in favor of `runtests.py`.
- Bump requirements, Github actions and pre-commit hooks.