Updated openstack/openstack
Project: openstack/heat  5da90ebee2a8213ebed41087454171799d5a30e4

Make Fn::Join give a better error message

When something goes wrong at the moment users are left staring hard
at their template trying to figure out whats wrong. We can make this a
lot easier by showing them the failed object.

Change-Id: If87447b7e160591505a68d857e8ef1751aac3723