Fix ansible-lint job
Fix ansible-lint job

The 'linters' tox environment was not running on roles, it was only
running on playbooks. This change adds a command to the linters
environment to ensure all roles are linted. This also cleans up a
comment in the tox file that was referring to a nonexistent zuul job.

Change-Id: I04d9d79fca16a7f78f9c646f96e5fba78a5f5329

openstack-infra/project-config,openstack-infra/project-config