chore(style): JSHint updates

@zaach r?
Here's the [es3](http://jshint.com/docs/options/#es3) docs from JSHint.com:
> _This option tells JSHint that your code needs to adhere to ECMAScript 3 specification. Use this option if you need your program to be executable in older browsers—such as Internet Explorer 6/7/8/9—and other legacy JavaScript environments._


1. No errors!
  ```js
/* jshint es3:false */
var obj = {name:'fan', age:'old',};
console.log(obj);
```

2. **Warning:** "Extra comma. (it breaks older versions of IE)"
  ```js
/* jshint es3:true */
var obj = {name:'fan', age:'old',};
console.log(obj);
```