kiji-modeling: EXP-278. Remove unused PMML configuration from ModelEnvironments.

issue: https://jira.kiji.org/browse/EXP-278
review: https://review.kiji.org/r/1330
commit: https://github.com/kijiproject/kiji-modeling/commit/9c119299f1cae0e677f1871f32205e89b95bc41f