As can be seen on https://github.com/systemd-cron/systemd-cron/releases, the current version of systemd-cron is 1.5.8.
https://github.com/systemd-cron/systemd-cron/releases/tag/v1.5.10 has been released. Please bump and add support for python3.4, 3.5 and 3.6.
Ok, thanks for the patience. 1.5.10 is in the tree. Mainly bugfixes so this will probably go stable in 30 days.