Right now, The Wikipedia Library stores cron logs indefinitely. This is taking up some needed database space. We should only keep cron logs for up to 100 days.

Luckily, django-cron has a configuration variable called DJANGO_CRON_DELETE_LOGS_OLDER_THAN that will do that for us. We should set this variable in the production and staging environments.

Reference: https://django-cron.readthedocs.io/en/latest/configuration.html