OpenSesame Flatpak Request

Project information: OpenSesame is a tool to create experiments for psychology, neuroscience, and experimental economics.
Homepage: http://osdoc.cogsci.nl
License: https://github.com/open-cogsci/OpenSesame/blob/loewenfeld/COPYING
Upstream has been contacted: https://github.com/open-cogsci/OpenSesame/issues/723