move-backlog fails: missing waterline

[Ana06]

move-backlog complains about waterline or seabed card needed with the waterline created.

> trollolo move-backlog --planning-board-id=M1puGZme --sprint-board-id=dsEc4bNv
/usr/lib64/ruby/gems/2.4.0/gems/trollolo-0.0.12/lib/scrum/backlog_mover.rb:24:in `setup': backlog list on planning board is missing waterline or seabed card (RuntimeError)
        from /usr/lib64/ruby/gems/2.4.0/gems/trollolo-0.0.12/lib/scrum/backlog_mover.rb:6:in `move'
        from /usr/lib64/ruby/gems/2.4.0/gems/trollolo-0.0.12/lib/cli.rb:371:in `move_backlog'
        from /usr/lib64/ruby/gems/2.4.0/gems/thor-0.20.0/lib/thor/command.rb:27:in `run'
        from /usr/lib64/ruby/gems/2.4.0/gems/thor-0.20.0/lib/thor/invocation.rb:126:in `invoke_command'
        from /usr/lib64/ruby/gems/2.4.0/gems/thor-0.20.0/lib/thor.rb:387:in `dispatch'
        from /usr/lib64/ruby/gems/2.4.0/gems/thor-0.20.0/lib/thor/base.rb:466:in `start'
        from /usr/lib64/ruby/gems/2.4.0/gems/trollolo-0.0.12/bin/trollolo:29:in `<top (required)>'
        from /usr/bin/trollolo:22:in `load'
        from /usr/bin/trollolo:22:in `<main>'