#4966 Add new JS tutorial (#4967)

* #4966 Add new JS tutorial

* Remove (youtube) and add list URL

free-courses-en.md

@@ -341,6 +341,7 @@
 * [Egghead.io](https://egghead.io)
 * [ES6 and Typescript Tutorial](https://www.youtube.com/playlist?list=PLC3y8-rFHvwhI0V5mE9Vu6Nm-nap8EcjV) - Codevolution
 * [Intro to JavaScript ES6 programming](https://www.youtube.com/playlist?list=PL-xu4i_QDSxcoDNeh8rx5-pHCCTOg0XsI)
+* [Intro To JavaScript Unit Testing & BDD](https://www.youtube.com/watch?v=u5cLK1UrFyQ&list=RDCMUC29ju8bIPH5as8OGnQzwJyA) - Traversy Media
 * [Javascript Essentials](https://www.udemy.com/javascript-essentials/) - Lawrence Turton (Udemy)
 * [Javascript30](https://javascript30.com) - Wesbos
 * [Learn how to program: JavaScript](https://www.learnhowtoprogram.com/javascript) - Epicodus Inc.