According to [1] files with no code shouldn’t contain any license header
or comments, and must be left completely empty. This patch cleaups the
code and enables H104 checking in the tox 'pep8' environment.
[1] https://docs.openstack.org/hacking/latest/user/hacking.html#openstack-licensing
Change-Id: I2528af3579b0426fff24796e94978fcba5001f6e