Add Drupal auth

Change-Id: I864678af62cb7279f9ad772a31b418ff75f6c377
Put passport-drupal in package.json

Change-Id: If5634e305bd918ad0b98cb658bbfd5fd57024c80
Show/hide login link, require login for data

Bail out on the data route if the user is not logged in, add an
endpoint to determine login status and use it to show the link
or a welcome message

Change-Id: Ib8fbe3885bffef7b598d98eb169ada7d981dce25