The Pywikibot installation on PAWS is out of date and is in need of and update to make sure users can take advantage of all the bug fixes and features.
The installation seems to be pinned very specifically to the following so there might be more to it then simply bumping the version.
git+https://gerrit.wikimedia.org/r/pywikibot/core.git@71e36c1574454d9438deaac08754ee4484dc4797#egg=pywikibot