Throw 404 for non-existent org for bulk_process

Fixes #1682
Merge branch 'master' into 1682-bulk-process
[#1682] Test that 404 is returned
[#1682] Fix pep8 issues
[#1682] clean up test code
[#1682] remove empty setup_class method
Merge pull request #1682 from ckan/1682-bulk-process

bulk_process page for non-existent organization throws Exception