Audit feed for settings and maybe some admin level events

Description

I would like to be able of hooking to some form of feed (I don't want it to be a log file as we have way too many of these) in which events like changing a setting will be published to.

I'm thinking of the issue that we are having right now in which many people can change settings in GitLab.com at free will, which is problematic in production because we have some assumptions of what is enabled or disabled and that may not be the case.

Proposal

I would just like to have some feed that I can hook up to so every time a setting is changed this gets pushed there and I can be notified either by pushing to slack or to any other place that I can use to be aware of these changes.

Documentation blurb

Overview

Use cases

Admins of GitLab.com and any other instance that is changing a lot all the time.

Feature checklist

Make sure these are completed before closing the issue, with a link to the relevant commit.