Rotate logs, reports

[danieldreier]

This module should set up cron jobs to compress/delete old reports, because that's a problem common to nearly all puppet masters.

(I'm planning on adding this eventually, just want to add a note so I remember)

[tampakrap]

I gave a thought on this, and I tend to believe we shouldn't logrotate in this module. We could use [https://github.com/yo61/puppet-logrotate](this logrotate module) as a dependency, but it needs to be configured first, and it makes more sense to use its logrotate::rule create_resources part to achieve that.

As for the cronjob, are we fine with a fixed montly one or do we want to make it more configurable and smarter?