Update Finagle.
More responsive scaling of partitions.

- ClusteredBeam: Immediately scale-up when restarting, if partitions increased.
- DruidBeamMaker: Use LinearShardSpecs, since otherwise, immediate scale-up
                  would break things.
HashPartitionBeam: Consistent hashing instead of modulus.
Rename JavaApiSpec -> JavaApiTest.
Update druid, scala-util.
[maven-release-plugin] prepare release tranquility-0.1.20