Go metrics

Go Metrics is *probably* better than the home grown stuff we have now. Plus it gives you a path to actually store the metrics somewhere useful w/o having to write it.

We could also spin up multiple shuttles, each with it's own metrics registry for separation.

Still a WIP

## Checklist 

- [x] Remove custom program stats stuff
- [x] Convert metrics to go-metrics
- [x] Custom metrics emitter for logfmt style metrics