DRF test polishment.
DRF test polishment.
Introduce mvn-based publisher for sonatype.

- parent POM file defining H2O build process
- h2o-core POM file which allows for building and publishing h2o-core
- strict separation between application code and test code
  - moved all tests from main/java into test/java
  - refactored all dependencies from core code into test code
    - mainly TestUtil dependencies
  - create FrameUtils, VAUtils extracting helper functions from
    TestUtils
  - removed methods from TestUtils which are not used
- see more for sonatype requirements here:
  - https://docs.sonatype.org/display/Repository/Sonatype+OSS+Maven+Repository+Usage+Guide
Merge branch 'master' of github.com:0xdata/h2o
Merge branch 'MM_mvn_again'