7-Eleven and Slim Jim are set to be co-presenting partners of World Wrestling Entertainment’s annual SummerSlam pay-per-view on Sunday, Aug. 15 at 5pm PT/8ET at the Staples Center in Los Angeles. SummerSlam weekend kicks-off Thursday, Aug. 12, and includes a two-day fan extravaganza: SummerSlam Axxess, at Nokia Plaza at L.A. Live, sponsored the National Guard.…