DeleteTableTest should use ExternalMiniClusterITestBase
DeleteTableTest should use ExternalMiniClusterITestBase

Removing duplicate code from DeleteTableTest. This is just test cleanup.

Change-Id: Iad374c10c2ee8ce46095b827ee4d6d11eb44605b
Reviewed-on: http://gerrit.cloudera.org:8080/1713
Tested-by: Internal Jenkins
Reviewed-by: Todd Lipcon <2c763d726a8c2f6afda9be7e0e56a2caa6bb5e6b@cloudera.com>

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