A Libyan affiliate of the extremist Islamic State group claimed responsibility Wednesday for an attack on a Tripoli luxury hotel that killed 10 people, including an American and four Europeans. READ: Gunmen storm Tripoli hotel in Libya, Exclusive offers. Lowest rates. Book your next family hotel stay through the official Sheraton Hotels website. Experience Sheraton resort hotels today. CAIRO (AP) — An Islamic State affiliate in Egypt has claimed responsibility…