Clusterfest is back and they’ve finally dropped their highly anticipated lineup this morning, fulfilling their stated promise of “Comedy.Music.Comedy”. Headlining comedians set to perform during the 3-day festival June 21st-23rd around San Francisco’s Civic Center include: Emmy Award winner John Mulhaney, comedy legend Patton Oswalt, star of HBO’s Insecure Issa Rae, Brooklyn -99 star Chelsea…