Support for Java 11

[masc]

According to http://www.oracle.com/technetwork/java/javase/eol-135779.html

• Java 8 will EOL in January 2019
• Java 9 is EOL as of March 2018
• Java 10 is currently the latest supported release, but will EOL in September 2018
• Java 11 will be the next LTS release in September 2018

LightJason should complete the transition from Java 8 to 11 by September 2018, with a grace period until January 2019 when Java 8 EOLs.