Celery-director

Changed
- **Remove Python 3.7 support**

Fixed
- Upgrade redis and sentry requirements to fix security issues

Changed
- Bump environs and werkzeug packages
- Add Python 3.10 and 3.11 in supported versions

Fixed
- Increment the cancel wait between 2 tests

Added
- Add an optional comment when executing a workflow

Changed
- Bump Flower dependency

Fixed
- Fix importlib-metadata in specific version to avoid Py3.7
- Updrade sql requirements to support the online mode

Added
- Add workflow hooks (success and failure) feature
- Add possibility to relaunch workflow with the CLI
- Add possibility to cancel a workflow

Changed
- Bump Flower dependency

Added
- Add the definitions page used to list and execute workflows
- Add a sidebar to display the menu
- Add documentation about Flower usage
- Add per-task queue routing

Changed
- **Remove Python 3.6 support**
- Add Python 3.9 support
- UI doesn't include payload when listing all workflows
- Bump dependencies (black, celery, click, flask, mkdocs, psycopg2-binary, redis)

Fixed
- Upgrade itsdangerous package to avoid unwanted bump

Added
- Add `with_payload` query param when listing workflows
- Add a new API route to list the worflows definitions (`GET /definitions`)
- Add the `DIRECTOR_REPO_LINK` variable to customize the repository link in UI
- Add a switch button in the UI to enable/disable the dark theme

Changed
- Update WebUI to display all dates on the local user timezone (the offset is displayed along the side of each date)
- Update documentation to schedule a periodic workflow
- Bump dependency `PyAML` from 5.1.2 to 5.4.1

Fixed
- Fix typos on documentation

Added
- Add new keys (`interval`, `crontab`) to schedule periodic workflows (key `schedule` is still supported but should not be used anymore)
- Add cleanup Celery task and retention offset to flush old workflows in the database
- Add documentation about the custom user configuration
- Add documentation for API endpoint to relaunch workflow
- Add documentation to set up the built-in cleanup task