stan_utility is incompatible with pystan3

[henrysting]

Due to the incompatibly between the stan_utility(0.1.2) and the pystan (3.x), the test_script.py could not finish successfully now. A easy solution is keeping the tool work with pytstan 2 (e.g. 2.19.1.1, import pystan) rather than pystan 3 (import stan). Or else, the stan_utility has to be replaced or updated.

[domeckert]

Thanks for the report @henrysting . I hadn't noticed this upstream change.

As a workaround, in the "requirements.txt" file you can replace "pystan" with "pystan<3.0", this should force installation of an older version of stan. On the longer term we definitely to align with the upstream changes.

[henrysting]

Sounds good ! I confirm that the release 0.7.0 works well with pystan 2.