1. School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
2. Cambridge Machines Deep Learning and Bayesian Systems (CMDLABS) Ltd, 22 Wycombe End, Beaconsfield, Buckinghamshire HP9 1NB, UK
3. Astrophysics Group, Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE, UK
4. Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, UK
5. Kavli Institute for Cosmology Cambridge, Madingley Road, Cambridge CB3 0HA, UK