Remove unused JDBC client from the voltkvqa test app.
Merge pull request #1609 from VoltDB/kvqa-jdbc-remove

Remove unused JDBC client from the voltkvqa test app.
MP OneShot benchmark: remove unused clients Async, Sync, JDBC from this voltkv clone
Merge branch 'master' of github.com:VoltDB/voltdb
Merge branch 'master' into httpexport