Photo By Peter Earl McCollough/Special to The ChronicleScreen Shot 2014-10-22 at 5.42.44 PMJoe Tuman speaks to voters in August. Three candidates running for mayor of Oakland who call themselves outsiders are asking voters to list them on their ballot and shun the three insiders favored to win the race. In a joint announcement, Joe Tuman, Bryan Parker and Courtney Ruby say they will hold a news conference on Thursday to “discuss why voters should choose a candidate from outside City Hall.” Currently the front-runners are councilwoman Rebecca Kaplan and Libby Shaaf and Mayor Jean Quan. “We’re not saddled with the baggage that they carry,” Tuman said in an interview. “The