Needham gold medalist Aly Raisman mingled with celebs in Los Angeles on Thursday night. The gymnast wore a simple white dress — and a flash of gold, of course — to the ArcLight for the premiere of the movie “Bachelorette,” a comedy starring Kirsten Dunst, Isla Fisher, and Lizzy Caplan. Raisman was nice enough to let Caplan — of “True Blood,” “New Girl,” and “Mean Girls” — try on her most important accessory during an interview with E!.