yonbergman/enumify — pull request #6 by ShayDavidson (2013-10-14 13:31:37+00:00)
Title: Added allow nil as an option

By default the enum field does not support a nil value. In order to allow nil values add the `allow_nil` option (similar to the Rails validation option).

```ruby
class Event < ActiveRecord::Base
enum :status, [:available, :canceled, :completed], :allow_nil => true
end

Event.create! # Is valid and does not throw an exception.
```