title: Invalidating existing users from RDS snapshot and creating new one while creating new instance from snapshot
body: <p>While creating new RDS aurora instance from snapshot I want to delete all existing users and add new users. I didn't find any aws cli command for this specific purpose. So I can invalidate all existing users and add new one.
  Does AWS provides this kind of functionality? If not then how we can do this while creating new RDS instance from snapshot? </p>