Add InfluxDB support for traefik metrics

vendor/github.com/VividCortex/gohistogram/histogram.go

@@ -0,0 +1,23 @@
+package gohistogram
+
+// Copyright (c) 2013 VividCortex, Inc. All rights reserved.
+// Please see the LICENSE file for applicable license terms.
+
+// Histogram is the interface that wraps the Add and Quantile methods.
+type Histogram interface {
+	// Add adds a new value, n, to the histogram. Trimming is done
+	// automatically.
+	Add(n float64)
+
+	// Quantile returns an approximation.
+	Quantile(n float64) (q float64)
+
+	// String returns a string reprentation of the histogram,
+	// which is useful for printing to a terminal.
+	String() (str string)
+}
+
+type bin struct {
+	value float64
+	count float64
+}