title: Gihub repo owner (Yii2-user) left repository - How to proceed?
body: <p><a href="https://github.com/dektrium/yii2-user">Yii2-user</a> is a very popular Yii2 extension for user management. There are lots of forks and contributors. Many issues and PRs are awaiting for being integrated or at least answered.</p>
  
  <p>But there is no activity from the repo owner since over 3 months which is very untypical for him compared to his activity before.</p>
  
  <p>Currently I am sitting on a fork and maintaining my branches. This works for a short time but I do not get PRs from the others and cannot sync with the original repo anymore.</p>
  
  <p>What is a common practice to make a repo survive if the owner abandons its repo (and cannot be reached)? How to proceed as a single fork owner and as community of all fork owners? </p>