Bump psycopg2-binary from 2.8.5 to 2.8.6

Bumps [psycopg2-binary](https://github.com/psycopg/psycopg2) from 2.8.5 to 2.8.6.
- [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-preview[bot] <support@dependabot.com>

requirements-test.txt

@@ -5,7 +5,7 @@ coverage==5.2.1 # pytest-cov
 pytest==6.0.1
 pytest-cov==2.10.1
 pytest-xdist==2.1.0
-psycopg2-binary==2.8.5; platform_python_implementation != "PyPy"
+psycopg2-binary==2.8.6; platform_python_implementation != "PyPy"
 psycopg2cffi==2.8.1; platform_python_implementation == "PyPy"
 port-for==0.4
 mirakuru==2.3.0