Merge pull request #1682 from mattfarina/show-off-goreportcard

feat(readme): Display the Go Report Card

README.md

@@ -1,6 +1,7 @@
 # Kubernetes Helm
 
 [![CircleCI](https://circleci.com/gh/kubernetes/helm.svg?style=svg)](https://circleci.com/gh/kubernetes/helm)
+[![Go Report Card](https://goreportcard.com/badge/github.com/kubernetes/helm)](https://goreportcard.com/report/github.com/kubernetes/helm)
 
 Helm is a tool for managing Kubernetes charts. Charts are packages of
 pre-configured Kubernetes resources.