Add plain pmml-evaluator test-case.

We use a naive-bayes-classifier to demonstrate the plain jpmml-evaluator API.
Added example R script to derive the naive bays model from the IRIS sample dataset.
Move PMML analytic into data science
Added abstraction to interact with r-project.

Added basic abstractions to interface with r-project.
Update maven plugin for spring-data-science

- This will allow other projects to add `spring-data-science` as a dependency
Revised the abstractions for interacting with R-Project.