Sample app to reproduce issue #77 of nested_form.

• clone that repo
• run bundle install
• run rake db:migrate (app uses sqlite)
• run rake db:seed (adding some sample data)
• run rails server and go to http://localhost:3000/users/new
• now try to add a user that likes to Biking in the Mountains and in the City
• when you edit that user again you will notice that either Mountain of City got lost
• now do mv nested_form_fix.js app/assets/javascripts/nested_form.js (pulled in #186) and test again - this time it should work