README.md: Fix npm & Bower badges to show PEG.js version

Based on a pull request by Daniel Baird (@DanielBaird):

  https://github.com/pegjs/pegjs/pull/419

README.md

@@ -1,6 +1,6 @@
 [![Build status](https://img.shields.io/travis/pegjs/pegjs.svg)](https://travis-ci.org/pegjs/pegjs)
-[![npm version](https://img.shields.io/npm/v/npm.svg)](https://www.npmjs.com/package/pegjs)
-[![Bower version](https://img.shields.io/bower/v/bootstrap.svg)](https://github.com/pegjs/bower)
+[![npm version](https://img.shields.io/npm/v/pegjs.svg)](https://www.npmjs.com/package/pegjs)
+[![Bower version](https://img.shields.io/bower/v/pegjs.svg)](https://github.com/pegjs/bower)
 [![License](https://img.shields.io/badge/license-mit-blue.svg)](https://opensource.org/licenses/MIT)
 
 PEG.js