Scalable Multi-Agent Reinforcement Learning for Warehouse Logistics with Robotic and Human Co-Workers - Aleksandar, Krnjaic; Steleac, Raul; Thomas, Jonathan; Papoudakis, Georgios; Schäfer, Lukas; Wing Keung To, Andrew; Lao, Kuan-Ho; Cubuktepe, Murat; Haley, Matthew; Börsting, Peter; Albrecht, Stefano