HubSpot/drop — pull request #34 by g00fy- (2014-09-25 08:46:27+00:00)
Title: Fix adding 'after-open' class on destroyed drops

Fix following scenario:
```javascript

drop = Drop({target:document.body,content:'test'});
drop.open();
drop.destroy();

```

throws
```Uncaught TypeError: Cannot read property 'classList' of null```