Aredis

* Fixbug: connection is disconnected before idel check, valueError will be raised if a connection(not exist) is removed from connection list

* Fixbug: abstract compat.py to handle import problem of asyncio.future

* Fixbug: When cancelling a task, CancelledError exception is not propagated to client

* Fixbug: XREAD command should accept 0 as a block argument

* Fixbug: In redis cluster mode, XREAD command does not function properly

* Fixbug: slave connection params when there are no slaves

* new: Dev conn pool max idle time (111) release connection if max-idle-time exceeded

* update: discard travis-CI

* Fix bug: new stream id used for test_streams

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* allow use of zadd options for zadd in sorted sets
* fix bug: use inspect.isawaitable instead of typing.Awaitable to judge if an object is awaitable
* fix bug: implicitly disconnection on cancelled error (84 )
* new: add support for `streams`(including commands not officially released

* fix bug: redis command encoding bug
* optimization: sync change on acquring lock from redis-py
* fix bug: decrement connection count on connection disconnected
* fix bug: initiation error of aws cluster client caused by not appropiate function list used
* fix bug: use `ssl_context` instead of ssl_keyfile,ssl_certfile,ssl_cert_reqs,ssl_ca_certs in intialization of connection_pool

* fix bug: connection with unread response being released to connection pool will lead to parse error, now this kind of connection will be destructed directly. [related issue](https://github.com/NoneGG/aredis/issues/52)

* fix bug: remove Connection.can_read check which may lead to block in awaiting pubsub message. Connection.can_read api will be deprecated in next release. [related issue](https://github.com/NoneGG/aredis/issues/56)

* add c extension to speedup crc16, which will speedup cluster slot hashing

* add error handling for asyncio.futures.Cancelled error, which may cause error in response parsing.

* sync optimization of client list made by swilly22 from redis-py

* add support for distributed lock using redis cluster