Merge pull request #125 from NETWAYS/makefile

Makefile and update README

Author: martialblog

Makefile

@@ -1,7 +1,7 @@
 .PHONY: test coverage lint vet
 
 build:
-	export CGO_ENABLED=0; go build
+	CGO_ENABLED=0 go build
 lint:
 	go fmt $(go list ./... | grep -v /vendor/)
 vet:

README.md

@@ -69,6 +69,8 @@ Flags:
 
 Determines the health of Logstash pipelines via "inflight events". These events are calculated as such: `inflight events = events.In - events.Out`
 
+Note that dropped are not considered here, this metric is just an approximation.
+
 Hint: Use the queue backpressure for Logstash 8.
 
 ```bash