[BUILD] Update version for 0.6.0-incubating rc2.

[BUILD] Update version for 0.6.0-incubating rc2.

[BUILD] Update version for 0.6.0-incubating rc1.

Apache Livy 0.5.0-incubating

Apache Livy 0.4.0-incubating release tag

Updated Livy version to 0.3.0.

Update version to 0.2.0.