[java client] - Also create a test package for the java client
[java client] - Also create a test package for the java client

We should create a tests package so that BaseKuduTest and and MiniKuduCluster
can be used by other projects just by adding a maven dependency. This also
adds a source jar that includes the test sources.

Change-Id: I20aef98ca4fe51eea02d7bc785482b8aa647bd81
Reviewed-on: http://gerrit.cloudera.org:8080/1450
Tested-by: Internal Jenkins
Reviewed-by: Jean-Daniel Cryans

EvilMcJerkface/kudu,EvilMcJerkface/kudu,cloudera/kudu,InspurUSA/kudu,helifu/kudu,cloudera/kudu,helifu/kudu,InspurUSA/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,cloudera/kudu,helifu/kudu,cloudera/kudu,andrwng/kudu,helifu/kudu,andrwng/kudu,cloudera/kudu,InspurUSA/kudu,andrwng/kudu,helifu/kudu,andrwng/kudu,helifu/kudu,andrwng/kudu,EvilMcJerkface/kudu,andrwng/kudu,InspurUSA/kudu,cloudera/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,cloudera/kudu,InspurUSA/kudu,InspurUSA/kudu,cloudera/kudu,EvilMcJerkface/kudu,helifu/kudu,EvilMcJerkface/kudu,cloudera/kudu,andrwng/kudu,andrwng/kudu,InspurUSA/kudu,helifu/kudu,InspurUSA/kudu,helifu/kudu,andrwng/kudu