Benp/new relic s3 agent

@mulby @brianhw @e0d

Even if we end up going with a different solution, this would be the first we roll out with. Please have a look?


This looks like it would work fine for monitoring at the bucket level of granularity.  If we were interested in *only* monitoring our tracking logs, we would need to actually count objects below the bucket level.  The current bucket where tracking logs are written is also the place where all other logs are also written.  The tracking logs are in a /logs/tracking root within the bucket.  It seems like the bucket_size would generalize to such an approach, but this looks like it would require a lot of rework, if it's even possible.