Bug, security code removing left zero and broken tests

When a user buys with a security code that starts with zero, Cielo returns the error below:

Cielo.Responses.Exceptions.ResponseException: O XML informado n o   valido: - string value '11' does not match pattern for type of codigo-seguranca element in DadosCartao in namespace http://ecommerce.cbmp.com.br: '<xml-fragment/>' 

This error occurs because the user input is, for example, 011 and the variable security code is a type int, so the left zero is removed sending only 11 to Cielo.