Fixed minor issue in AssetManagerTest

The last night  I've wasted more than 2 hours trying to fix a non-existent bug in the new I18NBundleLoader.
I was pretty desperate so I sought the help of @Mobidevelop on irc and he spent no more than 5 minutes to figure it out. lol
````
<@mobidevelop> That test is funky
<@mobidevelop> the way that test is made, the last item loaded will never return true for isLoaded
<@mobidevelop> because once the last item is loaded, everything gets unloaded
<@mobidevelop> If you move your asset load to the beginning, it will return true for isLoaded
````
So I decided to fix that funky test waiting for a reasonable amount of time (0.2 seconds) before reloading the assets.
This should prevent other unfortunate people from encountering the same issue.