Hey guys, I am from Brazil and would be useful to be able to pass a property in the date format from Brazil.
Is it ok if I submit a PR changing the line below to check it "johnzon.default-date-format" has a value then use it, if not use the default yyyyMMddHHmmssZ. https://github.com/apache/johnzon/blob/f28196b39ae3d0ff2ccdd8b1e9efe2a5801e1e7f/johnzon-mapper/src/main/java/org/apache/johnzon/mapper/MapperBuilder.java#L81 What do you think?
