Jasmine is a good testing framework with a great plugin ecosystem and widely used in other projects for this same use case (Rails + js).
Fixes #13748 - Add testing tools for code under webpack
This commit adds jest as a tool to be used to test some of the code
under webpack, supporting ES2015 via babel-polyfill.
The purpose of this is just to give the tools for other developers
By default, jest is automocking everything except for jQuery with this