Initial delivery of metrics code (#81)

* Initial delivery of metrics code

* Fix build issues

* Fix build issue with go vet

vendor/github.com/beorn7/perks/quantile/bench_test.go

@@ -0,0 +1,63 @@
+package quantile
+
+import (
+	"testing"
+)
+
+func BenchmarkInsertTargeted(b *testing.B) {
+	b.ReportAllocs()
+
+	s := NewTargeted(Targets)
+	b.ResetTimer()
+	for i := float64(0); i < float64(b.N); i++ {
+		s.Insert(i)
+	}
+}
+
+func BenchmarkInsertTargetedSmallEpsilon(b *testing.B) {
+	s := NewTargeted(TargetsSmallEpsilon)
+	b.ResetTimer()
+	for i := float64(0); i < float64(b.N); i++ {
+		s.Insert(i)
+	}
+}
+
+func BenchmarkInsertBiased(b *testing.B) {
+	s := NewLowBiased(0.01)
+	b.ResetTimer()
+	for i := float64(0); i < float64(b.N); i++ {
+		s.Insert(i)
+	}
+}
+
+func BenchmarkInsertBiasedSmallEpsilon(b *testing.B) {
+	s := NewLowBiased(0.0001)
+	b.ResetTimer()
+	for i := float64(0); i < float64(b.N); i++ {
+		s.Insert(i)
+	}
+}
+
+func BenchmarkQuery(b *testing.B) {
+	s := NewTargeted(Targets)
+	for i := float64(0); i < 1e6; i++ {
+		s.Insert(i)
+	}
+	b.ResetTimer()
+	n := float64(b.N)
+	for i := float64(0); i < n; i++ {
+		s.Query(i / n)
+	}
+}
+
+func BenchmarkQuerySmallEpsilon(b *testing.B) {
+	s := NewTargeted(TargetsSmallEpsilon)
+	for i := float64(0); i < 1e6; i++ {
+		s.Insert(i)
+	}
+	b.ResetTimer()
+	n := float64(b.N)
+	for i := float64(0); i < n; i++ {
+		s.Query(i / n)
+	}
+}