Aioredlock

Changed
- Support for aioredis version to 1.0.0.
- Complite lock refactoring using lua scripts .
- ``Aioredlock.extend(lock)`` is implemented to extend the lock lifetime.
- The lock manager now raises the ``LockError`` exceptions if it can not lock, extend or unlock the resource.
- The lock now can be released with async context manager.
- Support the same address formats as aioredis does.
- ``Aioredlock.is_locked()`` is implemented to check is the resource acquired by another redlock instance.
- The ``lock_timeout`` and ``drift`` parameters now mesured in seconds, just like ``retry_delay_min`` and ``retry_delay_max``.

Changed
- Updated aioredis requirement version to 0.3.1.
- Incremented the maxsize connections pool from default to 100.

Fixed
- Fixed a bug regarding the asyncio lock usage when creating the connection pool with redis.

Added
- Drift time check. See https://redis.io/topics/distlock#is-the-algorithm-asynchronous

Changed
- Randomized the retry delay for trying to acquire the lock again (range between 0.1 and 0.3 seconds).

Added
- aioredlock first version with all the basic distributed lock manager functionalities.