node update yarn code example

Example 1: install yarn

npm install -g yarn

Example 2: ubuntu install yarn

curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list

Example 3: upgrade node via yarn

$ npm i -g yarn
$ yarn global add yarn
$ npm rm -g yarn