kiji-schema: SCHEMA-610. KijiTableReaderOptions Builder should return a built reader instead of an Options object

issue: https://jira.kiji.org/browse/SCHEMA-610
review: https://review.kiji.org/r/1494
commit: https://github.com/kijiproject/kiji-schema/commit/98768e82f144fd4dbcb98511f64c248eecfa5cca