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.