Need to use Node v12.13.0 to run

[tristandenyer]

Suggesting adding line for node to package.json to let users know which version this works with.
I tried it with v13.1.0 and it did not work.
nvm use v12.13.0 got it working.

The following in package.json could help users:

  "engines": {
    "node": "12.13.0"
  },

You may want to add the Node version to this tutorial as well: https://applitools.com/tutorials/screenshots-javascript.html#running-tests-with-applitools