Prepare release v1.5.0

Prepare Release 1.4.0

Update kafka library for Kafka 2.8.0 support

This update also includes a few bug fixes, which were especially noticable during broker restarts

Prepare release 1.3.0

Add release note for release 1.2.2

correctly handle complex data in message headers; fixes redpanda-data…

…#143

Release v1.2.0

Prepare Release 1.1.0

Update changelog for 1.0.0 release

Fix partition consumer for edge case with high watermarks