Add GoReportCard Widget

Author: asifdxtreme

README.md

@@ -2,6 +2,7 @@
 
 [![Build Status](https://travis-ci.org/kubernetes-incubator/bootkube.svg?branch=master)](https://travis-ci.org/kubernetes-incubator/bootkube)
 [![GoDoc](https://godoc.org/github.com/kubernetes-incubator/bootkube?status.svg)](https://godoc.org/github.com/kubernetes-incubator/bootkube)
+[![Go Report Card](https://goreportcard.com/badge/github.com/kubernetes-incubator/bootkube)](https://goreportcard.com/report/github.com/kubernetes-incubator/bootkube)
 
 Bootkube is a tool for launching self-hosted Kubernetes clusters.