created sample spy test on chrome api

tests/helpers/Chrome.spec.js

@@ -0,0 +1,11 @@
+var chai = require('chai');
+var sinon = require('sinon');
+var chrome = require('sinon-chrome');
+var expect = chai.expect;
+
+describe('Chrome Dev Tools', function() {
+    it('should work', function() {
+        chrome.browserAction.setTitle({title: 'hello'});
+        sinon.assert.calledOnce(chrome.browserAction.setTitle);
+    });
+});