kiji-scoring: SCORE-96. Create a Scoring Server Aware Producer

issue: https://jira.kiji.org/browse/SCORE-96
review: https://review.kiji.org/r/1136
commit: https://github.com/kijiproject/kiji-scoring/commit/5193c9b38ce52e2c76ef78dd9f2d20b196a982d2