updated javadoc plugin

[ennerf]

Apparently my mvn package issue from #27 was caused by a bug in the javadoc-plugin: https://issues.apache.org/jira/browse/MJAVADOC-581

I'm not sure why the path D:\Github\chart-fx would cause any issues, but updating to the latest version fixes it.

[wirew0rm]

Had to revert, because the newer javadoc plugin seems to enforce stricter rules.
See https://travis-ci.org/GSI-CS-CO/chart-fx/builds/584011977#L1733.
At the moment there is unfortuately no time to hunt all these javadoc errors.
Does javadoc generation work for you locally?

[ennerf]

Weird. Yes, it works locally for me. I tested it with

# mvn -v
Apache Maven 3.6.2 (40f52333136460af0dc0d7232c0dc0bcf0d9e117; 2019-08-27T17:06:16+02:00)
Maven home: C:\Program Files\Java\apache-maven-3.6.2\bin\..
Java version: 11.0.1, vendor: Oracle Corporation, runtime: C:\Program Files\Java\jdk-11.0.1
Default locale: en_US, platform encoding: Cp1252
OS name: "windows 10", version: "10.0", arch: "amd64", family: "windows"

[ennerf]

This is apparently a bug in javadoc: https://bugs.openjdk.java.net/browse/JDK-8212233. Some Java versions work, some don't.

On my computer:

• Oracle JDK 11.0.1 [works]
• Azul Zulu 11.0.2 [fails] (<- travis version)
• Azul Zulu 11.0.4 [works]
• Azul Zulu 12.0.2 [fails]

It was supposedly fixed in 11.0.3, but travis uses the broken 11.0.2.

It probably doesn't make sense to add until travis upgrades 👎 I'll deal with it locally until then.