PHAT: PHoto-z Accuracy Testing by Hildebrandt, H, Arnouts, S, Capak, P, Moustakas, L, Wolf, C, Abdalla, F, Assef, R, Banerji, M, Benitez, N, Brammer, G, Budavari, T, Carliles, S, Coe, D, Dahlen, T, Feldmann, R, Gerdes, D, Gillis, B, Ilbert, O, Kotulla, R, Lahav, O, Li, I, Miralles, J, Purger, N, Schmidt, S, Singal, J