Log Message:
4.1.0

- Configuration: CELERY_SEND_EVENTS instead of CELERYD_SEND_EVENTS for 3.1.x \ 
compatibility
- App: Restore behavior so Broadcast queues work.
- Sphinx: Make appstr use standard format
- App: Make id, name always accessible from logging.Formatter via extra
- Worker: Add worker_shutting_down signal
- PyPy: Support PyPy version 5.8.0
- Results: Elasticsearch: Fix serializing keys
- Canvas: Deserialize all tasks in a chain
- Systemd: Recover loglevel for ExecStart in systemd config
- Sphinx: Use the Sphinx add_directive_to_domain API.
- App: Pass properties to before_task_publish signal
- Results: Add SSL option for Redis backends
- Beat: celery.schedule.crontab: fix reduce
- State: Fix celery issues when using flower REST API
- Results: Elasticsearch: Fix serializing document id.
- Beat: Make shallow copy of schedules dictionary
- Beat: Populate heap when periodic tasks are changed
- Task: Allow class methods to define tasks
- Platforms: Always return boolean value when checking if signal is supported.
- Canvas: Avoid duplicating chains in chords
- Canvas: Lookup task only if list has items
- Results: Allow unicode message for exception raised in task
- Python3: Support for Python 3.6
- App: Fix retried tasks with expirations
- * Fixes items format route in docs
- Utils: Fix maybe_make_aware
- Task: Fix task ETA issues when timezone is defined in configuration
- Concurrency: Consumer does not shutdown properly when embedded in gevent \ 
application
- Canvas: Fix 3725: Task replaced with group does not complete
- Task: Correct order in chains with replaced tasks
- Result: Enable synchronous execution of sub-tasks
- Task: Fix request context for blocking task apply (added hostname)
- Utils: Fix task argument handling
- Beat: Provide a transparent method to update the Scheduler heap
- Beat: Specify default value for pidfile option of celery beat.
- Results: Elasticsearch: Stop generating a new field every time when a new \ 
result is being put
- Results: Elasticsearch now reuses fields when new results are added.
- Results: Fixed MongoDB integration when using binary encodings
- Worker: Making missing ``*args`` and ``kwargs`` in Task protocol 1
return empty value in protocol 2.
- App: Fixed :exc:`TypeError` in AMQP when using deprecated signal
- Beat: Added a transparent method to update the scheduler heap.
- Task: Fixed handling of tasks with keyword arguments on Python 3
- Task: Fixed request context for blocking task apply by adding missing
  hostname attribute.
- Task: Added option to run subtasks synchronously with
  ``disable_sync_subtasks`` argument.
- App: Fixed chaining of replaced tasks.
- Canvas: Fixed bug where replaced tasks with groups were not completing
- Worker: Fixed problem where consumer does not shutdown properly when
  embedded in a gevent application.
- Results: Added support for using AWS DynamoDB as a result backend.
- Testing: Added caching on pip installs.
- Worker: Prevent consuming queue before ready on startup.
- App: Fixed task ETA issues when timezone is defined in configuration
- Utils: ``maybe_make_aware`` should not modify datetime when it is
  already timezone-aware.
- App: Fixed retrying tasks with expirations.
- Results: Allow unicode message for exceptions raised in task
- Canvas: Fixed :exc:`IndexError` raised when chord has an empty header.
- Canvas: Avoid duplicating chains in chords.
- Utils: Allow class methods to define tasks.
- Beat: Populate heap when periodic tasks are changed.
- Results: Added support for Elasticsearch backend options settings.
- Events: Ensure ``Task.as_dict()`` works when not all information about
  task is available.
- Schedules: Fixed pickled crontab schedules to restore properly.
- Results: Added SSL option for redis backends