Let's learn how to use React Router v4 Pre-release, and find out difference from the older versions.

Links:
React Router v4 Pre-release Documentation(https://react-router-website-xvufzcovng.now.sh/)
Should I use React.createClass, ES6 Classes or stateless functional components? (http://jamesknelson.com/should-i-use-react-createclass-es6-classes-or-stateless-functional-components/)
React-Router v4 FAQ (https://github.com/ReactTraining/react-router/blob/v4/README.md#v4-faq)
Github repo(https://github.com/velopert/react-router-4-demo.git)