Add include_blank option

I was using FancySelect with SimpleForm in my Rails application. I passed to SimpleForm collection_select input :include_blank option and it didn't appear in the option list when I applied FancySelect.
So, I've added an opportunity to keep the blank option in the option list by passing an argument to FancySelect like this:
var mySelect = $('.my-select');
mySelect.fancySelect({include_blank: true});