Updates for pom dependencies and many features

Summary of changes: 

Add on-success callback to the HBaseDbharness
Update many dependencies and increase minor version, 1.2.x -> 1.3.0
Support multiGet
Fix bug in Cas operations
Add Double op
Name the flusher threads better.
Allow for larger caches that will invalidate under memory pressure.
Expose cache metrics.
Redesign bucketer system for multiple buckets per dimension
Add release notes
Add instructions/workflow for doing a release
Add worked example about counting tweets, initial simple version
Include tests as a build artifact