remove rails 4.2 deprecated method column_for_attribute

This code specifically checks that the column type is boolean. I haven't tested it, but it seems like it should be changed to:
```ruby
if item.respond_to? :type_for_attribute # When was this introduced?
  item.type_for_attribute(data) == :boolean
elsif item.respond_to? :column_for_attribute
  attr = item.column_for_attribute(data) and attr.type == :boolean
end