Add support for Oracle Java 8

issue #1048 
Could you add the standard [RETCODE](https://github.com/TechEmpower/FrameworkBenchmarks/blob/master/toolset/setup/linux/systools/maven.sh#L3) bit, so that back-to-back calls of this file don't cause fairly large delays while we re-run apt-get for no reason. 

Note: Instead of `return 0`, you need  to run `update-alternatives` and then `return 0`