Upgrade dataflow sdk, fix pcoa output

Note: this fails when running on gce. Fix forthcoming.
Delete unused methods
Update readme
Fix bundled jar
Use common sharding logic from utils-java
Add travis and coveralls, prep for sonatype

Fixes #17
Add travis and coveralls images
Update name
[maven-release-plugin] prepare release google-genomics-dataflow-v1beta2-0.1
[maven-release-plugin] prepare for next development iteration
Add maven instructions