DataDog and StatsD Metrics Support

* Added support for DataDog and StatsD monitoring
* Added documentation

vendor/github.com/go-kit/kit/log/nop_logger.go

@@ -0,0 +1,8 @@
+package log
+
+type nopLogger struct{}
+
+// NewNopLogger returns a logger that doesn't do anything.
+func NewNopLogger() Logger { return nopLogger{} }
+
+func (nopLogger) Log(...interface{}) error { return nil }