merge develop
change ordered_logistic_rng test case so it fails with current code
fixed ordered_logistic_rng indexing
thanked Matius Simkovic in the acknowledgements
Merge branch 'develop' into bugfix/issue-688-ordered-logistic-rng
Merge pull request #694 from stan-dev/bugfix/issue-688-ordered-logistic-rng

fixes #688. Bugfix/issue 688 ordered logistic rng