title: Is it possible to deliver more than one pass in a .PKPASS file?
body: <p>use case:
  A customer bought a flight for his family.
  Now he wants to download all boarding passes for his flight at once and store it in passbook.</p>
  
  <p>How can I solve this problem?
  Can I add more than one pass descriptions in a pass.json?
  Or is it possible to reference more than one pass.json files in the manifest.json?</p>