Bump port-for from 0.5.0 to 0.6.0

Bumps [port-for](https://github.com/kmike/port-for) from 0.5.0 to 0.6.0.
- [Release notes](https://github.com/kmike/port-for/releases)
- [Changelog](https://github.com/kmike/port-for/blob/master/CHANGES.rst)
- [Commits](kmike/port-for@v0.5.0...v0.6.0)

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

requirements-test.txt

@@ -4,6 +4,6 @@ pytest-xdist==2.2.1
 pytest-cov==2.12.0
 coverage==5.5 # pytest-cov
 rabbitpy==2.0.1
-port-for==0.5.0
+port-for==0.6.0
 mirakuru==2.3.0
 -e .[tests]