Fix example

Merge pull request redis#822 from go-redis/fix/receive-message-rework

Rework ReceiveMessage

Add changelog

Merge pull request redis#782 from go-redis/fix/sentinel-client

Export SentinelClient

Merge pull request redis#774 from robinhoodmarkets/fix-cluster-copy

reset cmdable.process when copying cluster client

Remove costly 'appendIfNotExists' and 'remove' call from PubSub (redi…

…s#743)

* remove costly 'appendIfNotExists' and 'remove' call from pubsub

Merge pull request redis#742 from go-redis/fix/with-context-wrap-process

Fix WithContext followed by WrapProcess

Merge pull request redis#737 from gbbr/context

cluster: add support for context.Context to ClusterClient and Ring

Fix doc

Fix proto.RedisError in slices