Track hits to /universe in segment.io

:fork_and_knife: 

https://trello.com/c/TkVJBv0p/178-add-universe-api-metrics-to-the-metrics-end-point

So, this is not entirely what was requested, as it's not part of the metrics endpoint.  But, we track hits to other places in segment.io, and it seemed like a natural fit for this.
`universe` seems like an odd column name. If the idea is to be able to add rows for additional metrics, I think I'd prefer to have a `total` column and a `label` column to identify the metric.