add a link to the InfluxDB reporter

README.md

@@ -123,3 +123,4 @@ Clients are available for the following destinations:
 
 * Librato - [https://github.com/mihasya/go-metrics-librato](https://github.com/mihasya/go-metrics-librato)
 * Graphite - [https://github.com/cyberdelia/go-metrics-graphite](https://github.com/cyberdelia/go-metrics-graphite)
+* InfluxDB - [https://github.com/vrischmann/go-metrics-influxdb](https://github.com/vrischmann/go-metrics-influxdb)