kiji-schema: SCHEMA-880. TestKijiTableReaderPool should use KijiClientTest

Also include same fix for TestRowDataColumnFamilyOps.

issue: https://jira.kiji.org/browse/SCHEMA-880
review: https://review.kiji.org/r/2072
commit: https://github.com/kijiproject/kiji-schema/commit/d497369b9d06ad37514264684bf90598605e0313