Travis: jruby-9.2.0.0 runs on Java 8

[olleolleolle]

The build failed like:

Exception in thread "main" java.lang.UnsupportedClassVersionError: org/jruby/Main : Unsupported major.minor version 52.0
    at java.lang.ClassLoader.findBootstrapClass(Native Method)
    at java.lang.ClassLoader.findBootstrapClassOrNull(ClassLoader.java:1073)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:414)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:412)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:312)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)

https://stackoverflow.com/questions/10382929/how-to-fix-java-lang-unsupportedclassversionerror-unsupported-major-minor-versi

The proposed fix is to only offer Java 8 to JRuby 9.2.0.0.

Result: This change makes the build start, run, and then reporting having 1 failing test.

[olleolleolle]

The failing test has been reported as an Issue: https://github.com/cheald/manticore/issues/75

[olleolleolle]

@cheald Could I suggest merging this, until we have some more time to get to #75? Since, the current failure is kind of less interesting than #75.

[cheald]

Will do. Thanks!