title: Incorrect Passbook file
body: <p>I generate Passbook's files (.pkpass) with <a href="https://github.com/tschoffelen/PHP-PKPass" rel="nofollow">this library</a>.
  On my Mac, the generated file opens correctly.
  But when I click on "Add to Passbook" the file is not added on my iPhone. And when I send the file by e-mail on my iPhone, his name is "(null)" and I can't open it.
  Why my pkpass file is incorrect ?</p>