Selinon

Fixed
- Fixed race condition when using multiple workers with filesystem storage 163
- No password is now correctly propagated to Redis storage adapter 161

Credits
- thanks to vlagorsse for reporting and fixing the filesystem storage race
condition

Added
- new optional method `delete` in `StoragePool` to cleanup results of a task
- new `STORAGE_DELETE` and `STORAGE_DELETED` traces emitted on
DataStorage.delete

Credits
- thanks to vlagorsse for `DataStorage.delete` and new delete related traces
emitted

Fixed
- 153: AsyncResult is not serializable to json - thanks to vlagorsse

Fixed
- CLI executor now properly handles retrieval of exceptions for failed tasks

Removed
- Old Raven client for Sentry integration substituted with Sentry-SDK

Added
- Configuration of Sentry using environment variables
- Added a new event emitted by message producer - FLOW_SCHEDULE
- Shiped adapters now support configuration based on environment variables
- This changelog file to track notable release changes