Add Babel6 to project

[guyellis]

• Add Babel 6 to project.
• Add appropriate initialization calls/references so that tests and other files so that ES6 is available.
• Add an ES6 function (not in Node*) to test suite to confirm that it works.
• Add an ES6 function (not in Node*) to target code to confirm that it works.
• Node has some ES6 functionality. To test that Babel is doing the transpiling add something that Node doesn't have.

[guyellis]

Closing this in favor of using Node 7.x