iban.rb in buckaruby-1.1.0

- old
+ new

@@ -1,4 +1,6 @@
+# frozen_string_literal: true
+
 module Buckaruby
   # Helper for calculating the IBAN for a given account number, bank code and country code.
   class Iban
     def self.calculate_iban(account_number, bank_code, country_code = "NL")
       if account_number.nil? || account_number.to_s.empty?