XD-1060 XD-1182 add hdp20 and shdp M5

Squashed below commits:
- XD-1182 Switching back to hadoop12 as default for build to get all tests to pass
- XD-1182 Updating stub test class to match new method signatures
- XD-1060 XD-1182 Adding hdp20 as Hadoop distro; updating to spring-data-hadoop 2.0.0.M5