Shopify/active_merchant — pull request #539 by alex3t (2012-12-29 05:40:43+00:00)
Title: Authorize.net CIM response message can be hash

If more then one error then Authorize.net return array of hashes as:
{"messages"=>{"result_code"=>"Error", "message"=>[{"code"=>"E00015",
"text"=>"The field length is invalid for ABA Routing Number."},
{"code"=>"E00015", "text"=>"The field length is invalid for Bank
Account Number."}]}}