Allow destroying of blank html versions
Fix importer by adding back in the reject_if condition
Skip if the record is marked_for_destruction
Controller test to ensure the param is set

And the html version is destroyed

NS: you always need to pass an ID even with a has_one when using nested
attributes
Fix indentation
Merge pull request #625 from alphagov/destroy-html-version-of-publication

https://www.pivotaltracker.com/story/show/51986337

Destroy html version of publication