kiji-express: EXP-379. schema validation in KijiScheme doesn't account for column families

issue: https://jira.kiji.org/browse/EXP-379
review: https://review.kiji.org/r/1525
commit: https://github.com/kijiproject/kiji-express/commit/f9ad75d71489f29ec5020be64ce04581c26eae38