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/PostgresConfigParser.spec.js

@@ -1,4 +1,4 @@
-const parser = require('../src/Adapters/Storage/Postgres/PostgresConfigParser');
+const parser = require('../lib/Adapters/Storage/Postgres/PostgresConfigParser');
 
 const queryParamTests = {
   'a=1&b=2': { a: '1', b: '2' },