Create a function that takes date in the format yyyy/mm/dd as an input and returns "Bonfire toffee" if the date is October 31, else return "toffee".
halloween("2013/10/31") ➞ "Bonfire toffee"
halloween("2012/07/31") ➞ "toffee"
halloween("2011/10/12") ➞ "toffee"
N/A