README: force goreportcard to refresh badge by appending a request parameter

README.md

@@ -2,7 +2,7 @@
 [![Build Status](https://travis-ci.org/ugorji/go.svg?branch=master)](https://travis-ci.org/ugorji/go)
 [![codecov](https://codecov.io/gh/ugorji/go/branch/master/graph/badge.svg)](https://codecov.io/gh/ugorji/go)
 [![GoDoc](http://img.shields.io/badge/go-documentation-blue.svg?style=flat-square)](http://godoc.org/github.com/ugorji/go/codec)
-[![rcard](https://goreportcard.com/badge/github.com/ugorji/go/codec)](https://goreportcard.com/report/github.com/ugorji/go/codec)
+[![rcard](https://goreportcard.com/badge/github.com/ugorji/go/codec?v=2)](https://goreportcard.com/report/github.com/ugorji/go/codec)
 [![License](http://img.shields.io/badge/license-mit-blue.svg?style=flat-square)](https://raw.githubusercontent.com/ugorji/go/master/LICENSE)
 
 # go/codec