This way, we will have no issue fitting the entire dataset on the free tier of Heroku
This happened when rebasing and converting to unavailable currencies. For instance, the following was returning empty hashes for dates prior to the release of the new Turkish Lira: https://frankfurter.app/1999-01-01..?from=USD&to=TRY
... along with some minor miscellaneous refactoring This finally completes fixerAPI/fixer#22