When using the import rake task rake db:articles:import without any additional parameters, this will import articles with UNTIL_UPDATE_DATE until the day before. We have a cron task to run this rake task every 24 hrs.
It would be better to use UNTIL_IMPORT_DATE until the current day by default. This not only immediately imports the most recent articles, but also overlaps the import - this might help if there is an issue with the import.
by default import from CrossRef Api until update-date today. Closes #149
Fixed tests for #149