SetupWizard, blank screen, JS Error "`virtual-dom"

[eviltrout (Robin Ward)]

Fixed here:

https://github.com/discourse/discourse/commit/32c9ad6f7f4ddab8e1339ea51a9c36a3a57cc9ee

It slipped through our continuous integration so I also spent some time making sure all the tests are running correctly and this won’t happen again.