Mark Shanahan Globe Staff  October 08, 2015     Continue reading below  The indictment last week of five members of Teamsters Local 25 on federal extortion charges got us thinking about, of all things, Led Zeppelin. Why? Because the allegations against the Teamsters, who are accused of harassing and intimidating the “Top Chef” staff, including the TV show’s host, Padma Lakshmi, are reminiscent of a story Stephen Davis tells in “Hammer of the Gods,” his best-selling book about the British rock ba