Elizabeth Olivas, 18, was all set to graduate as salutatorian of her Frankfort, Ind., high school class when she was forced to return to her native Mexico due to a technicality with her visa: She missed the application date by one day because of the leap year [1], the Indianapolis Star reports. Although Olivas has lived in Indiana since she was 4 years old, U.S. immigration law required her to fly to Mexico within six months of turning 18 in order to get a visa or green card — a trip she made one day late. The consequence? A three-year ban on returning to the United States…