Merge pull request #170 from LappleApple/patch-1

Added PGObserver to Metric & Metric Collection

README.md

@@ -407,6 +407,7 @@ ils and flask.
   * [Diamond](https://github.com/BrightcoveOS/Diamond) - Python based statistic collection daemon.
   * [Collectd](http://collectd.org/) - System statistic collection daemon.
   * [Collectl](http://collectl.sourceforge.net/) - High precision system performance metrics collecting tool.
+  * [PGObserver](https://github.com/zalando/PGObserver) - Monitoring solution for PostgreSQL databases that also works with AWS RDS.
   * [Statsd](https://github.com/etsy/statsd/) - Application statistic listener.
   * [tcollector](http://opentsdb.net/docs/build/html/user_guide/utilities/tcollector.html) - System statistic collection daemon written in Python for OpenTSDB