Added CORS allowed domains to storyboard server config.

Adds docs-draft and storyboard to the list of permitted CORS domains.
This depends on https://review.openstack.org/#/c/124197/, which
depends on https://review.openstack.org/#/c/124163/.

Also handled a couple of formatting nits.

Change-Id: I70d9fd1e133bef8bcbc34beed0c4039eb84d0bf0