closes #20 added metrics instrumentation and configuration to Fluo

It would be nice there was a 'Type' section where the metric type is listed and linked with dropwizard docs (i.e [Counter](https://dropwizard.github.io/metrics/3.1.0/getting-started/#counters), [Timer](https://dropwizard.github.io/metrics/3.1.0/getting-started/#timers), etc).