Conjur AMI reaper that clears out old/test AMIs

We create a lot of AMIs since they are auto-created during our CI process. We should clear out our old AMIs as we don't need them to keep AWS more manageable. Perhaps we can use this? https://github.com/bonclay7/aws-amicleaner.

We can clear out non-release AMIs older than a month to start. This can be run in Jenkins on a cron via pipeline. This may warrant its own repo.