JDK Travis Build Compile Testing
1.1 - OracleJDK6 testing fail for Sun/Oracle JDK 6 as its EOL since
November 2012.
1.2 - OPENJDK6 testing failed as maven-enforcer-plugin:1.3.1:enforce
(enforce-versions) on project jquaternion: Some Enforcer rules are not
compatible.
1.3 - OPENJDK8 testing failed as JDK 'openjdk8' is not known