test($anchorScroll): add missing scrollBy spy to the mock window

Author: petebacondarwin

test/ng/anchorScrollSpec.js

@@ -52,6 +52,7 @@ describe('$anchorScroll', function() {
     elmSpy = {};
     $provide.value('$window', {
       scrollTo: jasmine.createSpy('$window.scrollTo'),
+      scrollBy: jasmine.createSpy('$window.scrollBy'),
       document: document,
       navigator: {}
     });