Olympic and world 800-metre champion Caster Semenya is South Africa’s only nominee for the 2018 Laureus World Sports Awards. Semenya is up for honors in the World Sportswoman of the Year category and is up against Wimbledon champion Garbiñe Muguruza and an all-American quartet of Australian Open champion Serena Williams, 16-time world athletics championship medalist Allyson…