Muhammad Ali. Evander Holyfield. Lennox Lewis. Three boxers from an elite club of heavyweight greats to have been three-time world champions. Anthony Joshua can put his name on that exclusive list by disposing of a British rival who sees himself as the future of the sport’s marquee category. He can do it on quite the stage, too. Joshua, a darling of British boxing since winning Olympic gold at the London Games in 2012, is looking to complete his late-career rebuild by beating Daniel Dubois to...