Let users make radio questions required 

![screen shot 2014-12-30 at 4 09 10 pm](https://cloud.githubusercontent.com/assets/86435/5582876/4a567594-903e-11e4-87ce-dacf3dcf3214.png)

I could use this as an opportunity to test custom checkbox styles. I tried [iCheck](http://fronteed.com/iCheck/), which was the most promising, solution, but it would regularly stop responding to clicks for unclear reasons.