The Washington Capitals announced that they called up goaltender Mitch Gibson from the South Carolina Stingrays on Friday. The 24-year-old netminder will serve as a black ace. Gibson posted a 22-14-3 record in the ECHL this season with a 2.56 goals-against average, a .899 save percentage, and three shutouts. In two appearances with AHL Hershey,…