Update gunicorn requirement from ~=20.0.4 to ~=20.1.0

Updates the requirements on [gunicorn](https://github.com/benoitc/gunicorn) to permit the latest version.
- [Release notes](https://github.com/benoitc/gunicorn/releases)
- [Commits](benoitc/gunicorn@20.0.4...20.1.0)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

requirements.txt

@@ -6,7 +6,7 @@ Flask-Mail~=0.9.1
 Flask-Migrate~=2.7.0
 Flask-pyoidc~=3.7.0
 flask_sqlalchemy~=2.4.4
-gunicorn~=20.0.4
+gunicorn~=20.1.0
 onesignal-sdk~=2.0.0
 psycopg2-binary~=2.8.6
 pylint~=2.7.2