max-power/iban — pull request #1 by maser (2014-01-07 16:48:54+00:00)
Title: Fix “undefined method `strip' for nil:NilClass” in ActiveModel validator

If the attribute value is `nil`, validation fails with a `NoMethodError`. As the IBAN attribute might be optional in the model where the validation is used, I changed it to allow `nil` as a value instead of adding an error.

To validate presence, the user can still do `validates presence: true, iban: true`