https://gist.github.com/thbar/7dc97d3f5f6a52e4fa00
(obviously not to be used in a CI environment).
Also, if you want to make sure you get push notification for security updates, check out this:
http://thibautbarrere.com/how-to-get-push-notifications-for-...
(I get only critical stuff as pushes, and get notified even in the rare case that the rails security email goes to spam as it happened once previously).