- update to 2.1.1:
* Added a new ConsumerGroupState UNKNOWN. The typo state UNKOWN
is deprecated and will be removed in the next major version.
* Fix some Admin API documentation stating -1 for infinite
timeout incorrectly.
* Request timeout can't be infinite.
* Added `set_sasl_credentials`. This new method (on the
Producer, Consumer, and AdminClient) allows modifying the
stored SASL PLAIN/SCRAM credentials that will be used for
subsequent (new) connections to a broker
* Added support for Default num_partitions in CreateTopics
Admin API.
* Added support for password protected private key in
CachedSchemaRegistryClient.
* Add reference support in Schema Registry client.
* Added support for schema references.
* KIP-320: add offset leader epoch methods to the
TopicPartition and Message classes
* KIP-222 Add Consumer Group operations to Admin API.
* KIP-518 Allow listing consumer groups per state.
* KIP-396 Partially implemented: support for
AlterConsumerGroupOffsets.
* Added metadata to `TopicPartition` type and `commit()`
* Added `consumer.memberid()` for getting member id assigned to
* the consumer in a consumer group
* Implemented `nb_bool` method for the Producer, so that the
default (which uses len) will not be used.
This avoids situations where producers with
no enqueued items would evaluate to False
* Deprecated `AvroProducer` and `AvroConsumer`. Use