Removes need to use babel-register (#4865)

* Removes need to use babel-register

- Adds watch to watch changes when running the test to regenerate
- Tests are now pure node 8

* Adds timing to helper.js

* Update contribution guide

* Adds inline sourcemaps generation to restore coverage

* nits

spec/ParseGlobalConfig.spec.js

@@ -1,7 +1,7 @@
 'use strict';
 
 const request = require('request');
-const Config = require('../src/Config');
+const Config = require('../lib/Config');
 
 describe('a GlobalConfig', () => {
   beforeEach(done => {