[NPM] Use a shorthand syntax for running multiple npm scripts with npm-run-all

Running multiple scripts in series or in parallel can become very verbose. Using a tool such as npm-run-all can help reduce the amount of overhead you have to type in order to get the same behavior.

Install:

npm i -D npm-run-all      

"scripts": {
    "start": "node index.js",
    "test": "npm-run-all eslint stylelint mocha",
    "eslint": "eslint --cache --fix ./",
    "stylelint": "stylelint '**/*.scss' --syntax scss",
    "mocha": "mocha spec/ --require babel-register --watch"
  },      

By default:

"test": "npm-run-all eslint stylelint mocha",      

This will run in series.

"test": "npm-run-all --parallel eslint mocha stylelint",