public function load(ObjectManager $manager)
 {
     // Add admin
     $user = new User();
     $user->setUsername("admin");
     $user->setPassword("admin");
     $user->setSalt('');
     $user->setRoles(array('ROLE_ADMIN'));
     $manager->persist($user);
     // Add raspi
     $user = new User();
     $user->setUsername("raspi");
     $user->setPassword("raspi");
     $user->setSalt('');
     $user->setRoles(array('ROLE_RASPI'));
     $manager->persist($user);
     // On déclenche l'enregistrement
     $manager->flush();
 }