remove sleep in favor of an expectation *some* content
validate DOI on journal update
only validate doi if it exists
if DOI elements are empty, do not validate
Merge pull request #712 from Tahi-project/validate-journal-doi

Validate journal doi
Merge pull request #713 from Tahi-project/no-sleeps

remove sleep in favor of an expectation for *some* content
allow configuration of CAS via envvar