Dancing superstar Derek Hough is coming to Rhode Island on Oct. 20 as part of The Providence Journal's Life: Boomers and Seniors Expo.Hough is a two-time Emmy award winner; a New York Times bestselling author and the only six-time champion on the ABC series "Dancing With the Stars." He is currently a judge on the NBC series "World of Dance."The Life Expo will be held at Twin River Casino on Saturday, Oct.