Hey! Mastodon.py v1.4.0 is now out on PyPi, with support for just about everything up to Mastodon version 2.8.0, and many bugs fixed!
Changelog on Github: https://github.com/halcy/Mastodon.py/releases/tag/1.4.0
Documentation: https://mastodonpy.readthedocs.io/en/1.4.0/
PyPi Package: https://pypi.org/project/Mastodon.py/1.4.0/
Sorry for the long wait!