Added support for AWS CloudWatch

Added an implementation to publish events to AWS CloudWatch

README.md

@@ -137,3 +137,4 @@ 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)
+* AWS CloudWatch - [https://github.com/savaki/cloudmetrics](https://github.com/savaki/cloudmetrics)