* Added FailedJobRegistry.

* Added job.failure_ttl.

* queue.enqueue() now supports failure_ttl

* Added registry.get_queue().

* FailedJobRegistry.add() now assigns DEFAULT_FAILURE_TTL.

* StartedJobRegistry.cleanup() now moves expired jobs to FailedJobRegistry.

* Failed jobs are now added to FailedJobRegistry.

* Added FailedJobRegistry.requeue()

* Document the new `FailedJobRegistry` and changes in custom exception handler behavior.

* Added worker.disable_default_exception_handler.

* Document --disable-default-exception-handler option.

* Deleted worker.failed_queue.

* Deleted "move_to_failed_queue" exception handler.

* StartedJobRegistry should no longer move jobs to FailedQueue.

* Deleted requeue_job

* Fixed test error.

* Make requeue cli command work with FailedJobRegistry

* Added .pytest_cache to gitignore.

* Custom exception handlers are no longer run in reverse

* Restored requeue_job function

* Removed get_failed_queue

* Deleted FailedQueue

* Updated changelog.

* Document `failure_ttl`

* Updated docs.

* Remove job.status

* Fixed typo in test_registry.py

* Replaced _pipeline() with pipeline()

* FailedJobRegistry no longer fails on redis-py>=3

* Fixes test_clean_registries

* Worker names are now randomized

* Added a note about random worker names in CHANGES.md

* Worker will now stop working when encountering an unhandled exception.

* Worker should reraise SystemExit on cold shutdowns

* Added anchor.js to docs

* Support for Sentry-SDK (#1045)

* Updated RQ to support sentry-sdk

* Document Sentry integration

* Install sentry-sdk before running tests

* Improved rq info CLI command to be more efficient when displaying lar… (#1046)

* Improved rq info CLI command to be more efficient when displaying large number of workers

* Fixed an rq info --by-queue bug

* Fixed worker.total_working_time bug (#1047)

* queue.enqueue() no longer accepts `timeout` argument (#1055)

* Clean worker registry (#1056)

* queue.enqueue() no longer accepts `timeout` argument

* Added clean_worker_registry()

* Show worker hostname and PID on cli (#1058)

* Show worker hostname and PID on cli

* Improve test coverage

* Remove Redis version check when SSL is used

* Bump version to 1.0

* Removed pytest_cache/README.md

* Changed worker logging to use exc_info=True

* Removed unused queue.dequeue()

* Fixed typo in CHANGES.md

* setup_loghandlers() should always call logger.setLevel() if specified

This fixes #125.

Connections can now be set explicitly on Queues, Workers, and Jobs.
Jobs that are implicitly created by Queue or Worker API calls now
inherit the connection of their creator's.

For all RQ object instances that are created now holds that the
"current" connection is used if none is passed in explicitly.  The
"current" connection is thus hold on to at creation time and won't be
changed for the lifetime of the object.

Effectively, this means that, given a default Redis connection, say you
create a queue Q1, then push another Redis connection onto the
connection stack, then create Q2. In that case, Q1 means a queue on the
first connection and Q2 on the second connection.

This is way more clear than it used to be.

Also, I've removed the `use_redis()` call, which was named ugly.
Instead, some new alternatives for connection management now exist.

You can push/pop connections now:

    >>> my_conn = Redis()
    >>> push_connection(my_conn)
    >>> q = Queue()
    >>> q.connection == my_conn
    True
    >>> pop_connection() == my_conn

Also, you can stack them syntactically:

    >>> conn1 = Redis()
    >>> conn2 = Redis('example.org', 1234)
    >>> with Connection(conn1):
    ...     q = Queue()
    ...     with Connection(conn2):
    ...         q2 = Queue()
    ...     q3 = Queue()
    >>> q.connection == conn1
    True
    >>> q2.connection == conn2
    True
    >>> q3.connection == conn1
    True

Or, if you only require a single connection to Redis (for most uses):

    >>> use_connection(Redis())

This fixes #36.

This partially fixes #37.