Dumux Day, July 29 2020

TODOS:

• #905 (closed), #904 (closed) (evtl #546 (closed))-> @DennisGlaeser
• #907 (closed) -> @martins
• #903 (closed) !2219 (merged) -> @nedc
• #883 (closed) / #866 (closed) (installexternal) -> @felixw
• !2201 (closed), !2217 (closed) -> @kweis (@bernd)
• feature/sequential porten (@martins, @DennisGlaeser)
• Gallery -> @tkurz
• Gallery -> @heck (dumux-repositories/dumux-website!75)
• #573 (closed) -> @seitz