The `./tools` dir was not part of the LINTABLES in the `tox.ini`
which meant that pep8/pylint etc checks were not run on the tools
there.
This commit adds it and fixes the issues that `make lint` found.
This script reads the RUNNER entries from .gitlab-ci.yml and the
snapshot repo names from Schutzfile. It then prints which runners don't
have entries in Schutzfile and which Schutzfile entries don't have
runners.
This is slightly complicated by the fact that centos-stream reports
itself as centos. So when checking for missing entries they are
considered to be the same thing. eg. If centos is a RUNNER and
centos-stream is in Schutzfile it doesn't report anything missing.
