Merge pull request #80 from slok/dependabot/go_modules/contrib.go.opencensus.io/exporter/prometheus-0.4.0

Bump contrib.go.opencensus.io/exporter/prometheus from 0.3.0 to 0.4.0

Author: slok

go.mod

@@ -1,7 +1,7 @@
 module github.com/slok/go-http-metrics
 
 require (
-	contrib.go.opencensus.io/exporter/prometheus v0.3.0
+	contrib.go.opencensus.io/exporter/prometheus v0.4.0
 	github.com/emicklei/go-restful v2.15.0+incompatible
 	github.com/fasthttp/router v1.4.1
 	github.com/gin-gonic/gin v1.7.4