In version 1.x, ESLint and Stylelint were directly packaged with yProx-CLI as dependency.
This is not a good practice, because someone that use yProx-CLI would like to use a different version.
You should install them manually:
$ yarn add -D 'eslint@>=5.0.0' 'stylelint@>=9.0.0'
# or with npm
$ npm install --save-dev 'eslint@>=5.0.0' 'stylelint@>=9.0.0'
ESLint and Stylelint are now totally optional.