/**
  * Sends a verification email to a user.
  *
  * @param UserInterface $user
  *
  * @return bool
  */
 public function sendVerificationEmail(UserInterface $user)
 {
     $params = ['user_id' => $user->id(), 'type' => UserLink::VERIFY_EMAIL];
     // delete previous verify links
     $this->app['db']->delete('UserLinks')->where($params)->execute();
     // create new verification link
     $link = new UserLink();
     $link->create($params);
     // email it
     return $user->sendEmail('verify-email', ['verify' => $link->link]);
 }