To support variations on our local LMS sites files it is helpful to have
subdirectories where we can store variations.  At Stanford I'm using
this so I can store carnegie/lms.j2, a variation on our normal lms.j2.

To use you can call the role like this:
    - {'role': 'edxapp', 'openid_workaround': true, 'template_subdir': 'carnegie'}
This would be from your main playbook file, in my case
edx-west/carnegie-prod-app.yml.

While in here I noticed we weren't setting owner or perms on the
sites-available/XX files, fix that.