update package version in npm code example

Example 1: use npm to update packages to latest version

npm i -g npm-check-updates
ncu -u
npm install

Example 2: update npm package

Use npm|yarn outdated to see which modules have newer versions
Use npm update|yarn upgrade (without a package name) to update all modules
Include --save-dev|--dev if you want to save the newer version numbers to your package.json. (NOTE: as of npm v5.0 this is only necessary for devDependencies).
Use npm install package@major-version to update to major version