SHARK-197. hive-exec test artifacts needs to have correct classifiers.

Hive-proper tries to distinguish artifacts by using different names, and
keeping artifactId the same. Which would never work of course. The correct way
is to use classifiers.
Setting hive artifacts groupId to edu.berkeley.cs.shark, so it can be published to maven.cetral

    For more information see https://issues.sonatype.org/browse/OSSRH-7151