message: Fixed the test-watch script for jest
  package.json
diff: "lintfix": "eslint ./src --fix",
  "test-only": "jest",
  "test": "npm run lint && jest",
  - "test-watch": "npm run test-only -- --watch --watch-extensions js",
  + "test-watch": "npm run test-only -- --watch --watchAll",
  "start": "babel src -d dist --watch"
  },
  "devDependencies": {
  