update readme for usage of angular 2 beta 1

Author: KillerCodeMonkey

README.md

@@ -2,4 +2,4 @@
 AngularJS.de Pizza Service Tutorial App in Angular 2 TypeScript
 
 Based on:
-quickstart example from https://angular.io/docs/js/latest/quickstart.html with AngularJS 2.0.0-beta.0
+quickstart example from https://angular.io/docs/js/latest/quickstart.html with AngularJS 2.0.0-beta.1