Setup and managing Drupal 8 with composer, git and drush

How to manage a Drupal project with Composer and Git, just in case you are still
using .zip files and ftp :)

* How to use Git for your Drupal project
* Hot to add Composer in the mix
* Simple deployment steps for the poor (no CI/CD, just git, composer and bash)
* Managing security updates with composer
* Avoid common problems when working with other people on the same project
* Using config-management in Drupal 8 with drush+git