Add new testing tools to the list (Hacktoberfest accepted) :loudspeaker:

[Zoran Pandovski]

Add new testing tools that you have find useful to the existing lists 🙌

[Aayush Bisen]

Hey @ZoranPandovski 👋

Added an awesome framework Nightwatch.js in #52.

[Martin Sidorov]

Hi, added one more tool in #53