Composer without root
Run this in ~/composer: curl -sS https://getcomposer.org/installer | php
Put this in .bashrc: alias composer="php ~/composer/composer.phar"
Install Drupal 8 With Composer In Custom Web Folder
composer create-project drupal-composer/drupal-project:8.x-dev my_site_name_dir --no-interaction --no-install
Adjust web folder in composer.json file and then run "composer install".
Check available versions of a package
composer show package_name --available