Add ElasticSearch exporter (#675)
Add ElasticSearch exporter (#675)

This commit adds the ElasticSearch stats exporter
prometheus/docs,chosenken/docs,ddfreyne/prometheus-docs,open-falcon/open-falcon.github.io,prometheus/docs,chosenken/docs,du2016/prometheus-docs,Cepave/openfalcon.io,ddfreyne/prometheus-docs,ddfreyne/prometheus-docs,ddfreyne/prometheus-docs,open-falcon/open-falcon.github.io,prometheus/docs,chosenken/docs,du2016/prometheus-docs,du2016/prometheus-docs,Cepave/openfalcon.io,open-falcon/open-falcon.github.io,Cepave/openfalcon.io,chosenken/docs