By Jeff Sneider LOS ANGELES (TheWrap.com) – Rocket Pictures' Elton John biopic "Rocketman" will be taking off at Cannes, with Good Universe launching the international sales effort at the upcoming Cannes Film Market. Michael Gracey is directing from a script by Oscar nominee Lee Hall ("Billy Elliot"). Steve Hamilton Shaw and David Furnish ("Gnomeo and Juliet") will produce, while Sir Elton John will executive produce. …