A user can mark a task as done

[fynnfeldpausch]

As a user, I want to mark tasks as done so that I can see which tasks have already been worked on.

Acceptance criteria

• the user can mark a task as done
• the task list is sorted by done status
  • tasks that are not done go to the top of the list
  • tasks that are done go to the bottom of the list
• the user can clear the list of done tasks

Optional acceptance criteria

• the user can mark a task as done by drag & drop to the list of done tasks
• the user can set the task status with more details ("In Progress", "Blocked", ...)

Additional information
We prefer quality over quantity. Clean code is a given. We expect all test to run.