bump 2.0.0-beta.3
bump 2.0.0-beta.3

ng-book/angular2-rxjs-chat,ng-book/angular2-rxjs-chat,ng-book/angular2-rxjs-chat,ng-book/angular2-rxjs-chat,ahmadassaf/Angular-RxJS-Chat,ahmadassaf/Angular-RxJS-Chat,ahmadassaf/Angular-RxJS-Chat