new_contents: _USERS = {'admin': {'owner': '*', 'first_name': 'Databank', 'last_name': 'Admin', 'role': 'admin'}, 'sandbox_user': {'owner': ['sandbox'], 'role': 'user', 'name': 'Sandbox user', 'description': 'User for silo Sandbox'}}
  
subject: add users.py, which plugs a hole in the dev authentication process