Recent changes to org (not sure when), seem to have changed the type
of org-structure-template-alist

This broke org-reveal : https://github.com/yjwen/org-reveal

I suggested (without too much knowledge) the attached patch to the reveal folks
(Issue: https://github.com/yjwen/org-reveal/issues/315#issuecomment-355868192 )

Now someone has asked that that patch be made into a pull-request

It would be good if someone here can look at the patch in the light of
these recent changes and see
if the patch looks ok