ENH: Wires minutely emission of data from performance tracker.

Wires up performance tracker so that when `emission_rate` is set
to `minute`, the performance packets are sent out every minute,
instead of once per day.

Please note, the performance packets that are generated are not
ready for prime time consumption, this patch is merely a step towards
hooking up the ability to inspect minute data.

Known issues:
- The packets do not currently include risk information.
  Since we need to consider how this affects the denominators
  of the risk calculations.