kiji-scoring: SCORE-167. Infer result record schema from PMML DataDictionary.

issue: https://jira.kiji.org/browse/SCORE-167
review: https://review.kiji.org/r/1714
commit: https://github.com/kijiproject/kiji-scoring/commit/437a511dd88f2329897ce4561e005ff630fd5d92