Magicbell

Changed
- Update contributing for clarity for project
- Update flake8 checks

Added
- Code coverage collection with codecov.io

Added
- Add `MagicBell.connect` and `MagicBell.disconnect` methods for more ergonomic connection management.

Fixed
- Reorder `Notification` types to avoid forward ref issue in pydantic validation

First open source release of the SDK.

Added
- Initial repo setup with basic client and CI
- APIs supported:
- Create notification
- Create user
- Update user
- Delete user
- List projects
- Get project
- Create project
- Update project
- Delete project
- Updating channel configuration for a project (undocumented)
- Retrieve channel configuration for a project (undocumented)
- GraphQL queries