Merge branch 'renovate/github.com-openzipkin-zipkin-go-0.x' into 'master'

Update module github.com/openzipkin/zipkin-go to v0.4.0

See merge request !38

go.mod

@@ -19,7 +19,7 @@ require (
 	github.com/gorilla/handlers v1.5.1
 	github.com/lunixbochs/struc v0.0.0-20200707160740-784aaebc1d40
 	github.com/miscreant/miscreant.go v0.0.0-20200214223636-26d376326b75
-	github.com/openzipkin/zipkin-go v0.2.5
+	github.com/openzipkin/zipkin-go v0.4.0
 	github.com/prometheus/client_golang v1.12.1
 	github.com/russross/blackfriday/v2 v2.1.0
 	github.com/theckman/go-flock v0.8.1