title: How to deploy with Composer and Git without downtime?
body: <p>For our project we are using Git to version our code and Composer to handle the dependencies. That work quite well, but for updating or adding a dependency, I haven't found a good workflow. </p>
  
  <p>Let's assume, we want to add feature, that needs some new dependency. We would implement and test it in a feature branch. In this branch, we would update the composer.json file. After finishing the feature, we merge it using a pull request and deploy it with <code>git pull</code> on the server. The we would perform the <code>composer install</code> to install the new dependencies on the server. The issue with this workflow: for the time between the Git and Composer update, the system might be broken due to missing dependencies. </p>
  
  <p>How would you solve this in a workflow without any downtime and without a maintenance mode?</p>