[WW-5016] Adds support for LocalDate and adjusts tests to use the new Java 8 API

[lukaszlenart]

Relates to WW-5016

[coveralls]

Coverage increased (+0.02%) to 50.583% when pulling 59932a5 on WW-5016-uses-proper-format into f0b24d1 on master.

[JCgH4164838Gh792C124B5]

Hi @lukaszlenart.
The changes and updates to the unit tests seem to make sense, based on a migration from SimpleDateFormat to DateTimeFormatter. 👍
The only other consideration might be whether there would be any (or enough) value in providing a backwards-compatibility mode for the old date formatting ?
Probably not, but just raising it for consideration.

[lukaszlenart]

Hm... I can implement a flag to either use a new or an old formatting mechanism. Yet this will introduce unnecessary complexity and I think it's a good moment to break backward compatibility while releasing a new major version.

[lukaszlenart]

I'm working on a version which uses @Inject to inject a porper formatter.

[lukaszlenart]

Done, I've extended the change to use to a formatter injected by the framework based on user choice.