Imports
- github.com/kelseyhightower/envconfig
- github.com/prometheus/client_golang/prometheus
- github.com/prometheus/client_golang/prometheus/promauto
- github.com/prometheus/client_golang/prometheus/promhttp
- github.com/gorilla/mux
- github.com/elastic/go-elasticsearch/v6
- github.com/elastic/go-elasticsearch/v6/esutil
- github.com/sirupsen/logrus