When a character promises a life story so inspirational it’ll make a believer of an atheist, the tale better come through on some big-time convincing. Life of Pi, Lolita Chakrabarti’s stage adaption of Yann Martel’s heart-tugging 2001 novel opening tonight at Broadway’s Gerald Schoenfeld Theatre, won’t likely be churning out any religious converts, but renewed faith in the art of puppetry is all but guaranteed.