chore: consistent badge shape (angular#7053)

README.md

@@ -1,7 +1,7 @@
 [![Build Status](https://travis-ci.org/angular/angular.svg?branch=master)](https://travis-ci.org/angular/angular)
 [![Join the chat at https://gitter.im/angular/angular](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/angular/angular?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-[![Issue Stats](http://issuestats.com/github/angular/angular/badge/pr)](http://issuestats.com/github/angular/angular)
-[![Issue Stats](http://issuestats.com/github/angular/angular/badge/issue)](http://issuestats.com/github/angular/angular)
+[![Issue Stats](http://issuestats.com/github/angular/angular/badge/pr?style=flat)](http://issuestats.com/github/angular/angular)
+[![Issue Stats](http://issuestats.com/github/angular/angular/badge/issue?style=flat)](http://issuestats.com/github/angular/angular)
 [![npm version](https://badge.fury.io/js/angular2.svg)](http://badge.fury.io/js/angular2)
 [![Downloads](http://img.shields.io/npm/dm/angular2.svg)](https://npmjs.org/package/angular2)