Project Proposal: Improve and fix coala support for latest python versions

This project focuses on improving coala support for some of the latest python versions.

Currently, coala only supports python version 3.6 which is too old at the moment. Improving the support is not a trivial task and will involve a lot of research work. To help improve this process, we will drop support for some of the bears which are incompatible with the newer versions. As a part of the project CI builds should be green for both coala and coala-bears repositories with checks on python 3.6 to 3.9 (possibly).