Updated package file with scripts to run unit and e2e tests in headless mode

package.json

{
  "name": "angular-with-ci-cd",
  "version": "0.0.0",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e",
    
    "test_headless": "ng test --watch false --browsers ChromeHeadless",
    "e2e_headless": "ng e2e --protractor-config='e2e/ci.protractor.conf.js'",
    "all_tests": "yarn lint && yarn test_headless && yarn e2e_headless"
  }
}