THINK-13 TRN

API for Questions and Options. I ended up reverting my commit for fe because its too big for what I need.
Does this need to be random? I realize there are > 43 million possibilities for 3^16, but if it doesn't need to be random you could use something like this:

https://github.com/CruGlobal/missionhub/blob/master/lib/base62.rb
https://github.com/CruGlobal/missionhub/blob/3befb5abd5f27024028c232dcf42fab64cc928f8/app/controllers/sms_controller.rb#L114

This is essentially how url shortener services work. The size of the unique code grows at a slow rate.