#12 expose prometheus metrics endpoint

...rometheus/client_golang/prometheus/go_collector_latest.go

...thub.com/prometheus/client_golang/prometheus/histogram.go

...s/client_golang/prometheus/internal/go_runtime_metrics.go

...om/prometheus/client_golang/prometheus/internal/metric.go

.../github.com/prometheus/client_golang/prometheus/labels.go

.../github.com/prometheus/client_golang/prometheus/metric.go

...ithub.com/prometheus/client_golang/prometheus/observer.go

.../prometheus/client_golang/prometheus/process_collector.go

...theus/client_golang/prometheus/process_collector_other.go

...eus/client_golang/prometheus/process_collector_windows.go

...prometheus/client_golang/prometheus/promhttp/delegator.go

....com/prometheus/client_golang/prometheus/promhttp/http.go

...us/client_golang/prometheus/promhttp/instrument_client.go

...us/client_golang/prometheus/promhttp/instrument_server.go

...om/prometheus/client_golang/prometheus/promhttp/option.go

...ithub.com/prometheus/client_golang/prometheus/registry.go

...github.com/prometheus/client_golang/prometheus/summary.go

...r/github.com/prometheus/client_golang/prometheus/timer.go

...github.com/prometheus/client_golang/prometheus/untyped.go

...r/github.com/prometheus/client_golang/prometheus/value.go