Updates
- Officially drop support for Python 3.6. Sparkmagic will not guarantee Python 3.6 compatibility moving forward.
- Re-format all code with [`black`](https://black.readthedocs.io/en/stable/index.html) and validate via CI
Bug Fixes
- Fixed, simplified, and sped up the sparkmagic Docker images for local development and testing
- Adds support for `ipython>=8`
- Adds support for `ipykernel>=6`