Create the `Records` table.
Answer belongs to a record.
Add the `Record` model.
Add routes for `record`.
A category has many records.
Show a `Add Another Record` link with MultiRecord categories.
Add RecordsController#create.
After creating a record, it creates answers for all it's category's questions.
Removed the ResponsesController#sort_questions_by_order_number method.

We can call the sort method directly from the decorator.
Add Question#sorted_answers_for_response.
Add RadioQuestion#sorted_answers_for_response.
Add DropdownQuestion#sorted_answers_for_response & MultiChoiceQuestion#sorted_answers_for_response.
Added Category#sorted_answers_for_response.
Added MultiRecordCategory#sorted_answers_for_response.
Add Record#sorted_answers.
Answer delegates `order_number` to Question.
Add Response#sorted_answers.
When creating the form for a response, use Response#sorted_answers to get the answers in the correct order.
MultiRecordCategory#sorted_answers_for_response includes only records belonging to the given response.
When fetching sorted answers for a multi-record-category, fetch answers
for each of its records.