Slack integration should have a flag to notify 'freshly broken', 'still broken' and 'no longer broken' (the missing state being 'build still successful')

So, I've been playing with the slack integration and I think it's nice to notify users of a broken build.

However, if we're going to shame a developer with a broken build, we need to also give them props for fixing it.

Currently the integration will notify on all builds or only broken builds.

In addition to the 'only broken builds' i propose it also notifies slack 'build back to normal' for the first successful build after a failure Maybe this is a second checkbox.....