[Java] Use openjdk8 on OSX for Travis as they have gone crazy and defaulted to 13.
[Java] Use openjdk8 on OSX for Travis as they have gone crazy and defaulted to 13.

EvilMcJerkface/Aeron,EvilMcJerkface/Aeron,EvilMcJerkface/Aeron,mikeb01/Aeron,EvilMcJerkface/Aeron,real-logic/Aeron,real-logic/Aeron,mikeb01/Aeron,mikeb01/Aeron,mikeb01/Aeron,real-logic/Aeron,real-logic/Aeron