Updated positional arguments in keeping with PyMC3 changes for Ch2
Updated positional arguments in keeping with PyMC3 changes for Ch2

ifduyue/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,Fillll/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,aitatanit/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,aitatanit/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,CamDavidsonPilon/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,Fillll/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,chengwliu/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,CamDavidsonPilon/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,ifduyue/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,shhong/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,chengwliu/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,aitatanit/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,chengwliu/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,ifduyue/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,Fillll/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,shhong/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,CamDavidsonPilon/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers,shhong/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers