Mexicans voted to scrap a part-built $13 billion new airport for the capital in a divisive referendum pushed for by President-elect Andres Manuel Lopez Obrador, dealing a blow to business leaders like Carlos Slim, and causing the peso to slide. Roughly a million people, just 1 percent of Mexico’s electorate, participated in the referendum held over four days, the Arturo Rosenblueth Foundation, the non-profit organization that supervised the count…