kiji-model-repository: KIJIREPO-46. Add a PmmlModelRepoTool for creating model containers from PMML files.

issue: https://jira.kiji.org/browse/KIJIREPO-46
review: https://review.kiji.org/r/1720
commit: https://github.com/kijiproject/kiji-model-repository/commit/a38cd8f756231f9e52022834d86e4ce988790298