Update psycopg2-binary requirement from ~=2.8.3 to ~=2.8.6 (#217)

Updates the requirements on [psycopg2-binary](https://github.com/psycopg/psycopg2) to permit the latest version.
- [Release notes](https://github.com/psycopg/psycopg2/releases)
- [Changelog](https://github.com/psycopg/psycopg2/blob/master/NEWS)
- [Commits](https://github.com/psycopg/psycopg2/commits)

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements.txt

@@ -3,7 +3,7 @@ Flask-pyoidc~=2.2.0
 Flask-Mail~=0.9.1
 Flask-Gzip~=0.2
 flask_sqlalchemy~=2.3.2
-psycopg2-binary~=2.8.3
+psycopg2-binary~=2.8.6
 Flask-Migrate~=2.2.1
 pylint~=2.3.1
 gunicorn~=19.7.1