[Backend Dependencies Update] Update flask-httpauth to 4.2.0

[pyup-bot]

This PR updates Flask-HTTPAuth from 3.3.0 to 4.2.0.

Changelog

4.2.0

- Allow error response to return a 200 status code [114](https://github.com/miguelgrinberg/Flask-HTTPAuth/issues/114) ([commit](https://github.com/miguelgrinberg/Flask-HTTPAuth/commit/f3e6a5754e89cda30fa88ef8b9dfa31e1697a688))
- Add optional argument to MultiAuth class [115](https://github.com/miguelgrinberg/Flask-HTTPAuth/issues/115) ([commit](https://github.com/miguelgrinberg/Flask-HTTPAuth/commit/e3c6e5fb0481c14c326460408c2d0d038adf7ddc)) (thanks **pryankster** and **Michael Wright**!)
- Remove python 3.5 and add python 3.9 to build ([commit](https://github.com/miguelgrinberg/Flask-HTTPAuth/commit/507a7c0bfdf7da3bfb6a0cff9624295cf1119986))

4.1.0

- Basic authentication with custom scheme ([commit](https://github.com/miguelgrinberg/Flask-HTTPAuth/commit/1aaf872716cb46330fd49e89663da1a568e54f0b))

4.0.0

- Return user object from verify callbacks ([commit](https://github.com/miguelgrinberg/Flask-HTTPAuth/commit/51748c24f5aa53175b0f2712b814f7ea581f04e4))
- New role authorization support ([commit](https://github.com/miguelgrinberg/Flask-HTTPAuth/commit/8178f6dd74dab47b993ba532dd12f0cfdb5799f1)) (thanks **gemerden**!)
- Add a custom token authorization header option ([commit](https://github.com/miguelgrinberg/Flask-HTTPAuth/commit/575b46ade7188152e1b82de84be949bf3f8a300b)) (thanks **Mohamed Feddad**!)
- Support an optional=True argument in `login_required` decorator ([commit](https://github.com/miguelgrinberg/Flask-HTTPAuth/commit/8ecbb1157822360f5bdb24231fd50f25a6247620)) (thanks **Saif Almansoori**!)
- Pass HTTP status code to error callback ([commit](https://github.com/miguelgrinberg/Flask-HTTPAuth/commit/fc8bcd6772b53ef5cc14cd4c6199d63cd2c71f30))
- More secure example of basic auth in the documentation ([commit](https://github.com/miguelgrinberg/Flask-HTTPAuth/commit/0043e138cd99c7e9fa179ee30ad2283f9b8c704f))
- Fix broken links in CHANGES.md and changelog template [85](https://github.com/miguelgrinberg/Flask-HTTPAuth/issues/85) ([commit](https://github.com/miguelgrinberg/Flask-HTTPAuth/commit/96fafd43c2d0275f2d4042e95faefce24183ec02)) (thanks **Katie Smith**!)

Links

• PyPI: https://pypi.org/project/flask-httpauth
• Changelog: https://pyup.io/changelogs/flask-httpauth/
• Repo: http://github.com/miguelgrinberg/flask-httpauth/
• Docs: https://pythonhosted.org/Flask-HTTPAuth/

[pyup-bot]

Closing this in favor of #1025