$ curl -o- -L https://yarnpkg.com/install.sh | bash
$ yarn version
$ yarn init
$ yarn add express
$ yarn remove express
$ yarn add [email protected]
$ yarn upgrade [email protected]
$ yarn licenses generate-disclaimer
$ yarn why promise
$ curl -o- -L https://yarnpkg.com/install.sh | bash
$ yarn version
$ yarn init
$ yarn add express
$ yarn remove express
$ yarn add [email protected]
$ yarn upgrade [email protected]
$ yarn licenses generate-disclaimer
$ yarn why promise