----------------
Developed from 2021-02-25 to 2021-02-26.
- Dropped support for Python 3.4.
- Changed supported Python versions to 3.7, 3.8, and 3.9.
- Updated blinker to v1.4 (from v1.3).
- Updated Flask to v1.1.2 (from v0.10.1).
- Updated Werkzeug to v1.0.1 (from v0.15.0).
- Ported tests from unittest and nose2 to pytest.
- Remove usage of tox.
- Switched codebase to ``src/`` package layout.
- Moved package configuration from ``setup.py`` to ``setup.cfg``.
- Turned ``run_gewebehaken.py`` script into actual console entrypoint
script.
- Make log filename optional and configurable via command-line argument
``--logfile``.
- Require ``target_account_screen_name`` key to be passed to Twitter
endpoints.