Avro alerts, context manager, alert data consistency (v0.2.0)

What's Changed

• Added avro option to kafka stream by @elvinpoole in #1
• Alert generation: enforce consistent cutout sizes within alerts and RA/DEC are in Rubin's field of view
• Add a context manager to avoid having to call lass.startbroker() and lass.removebroker
• Housekeeping: Publish to pypi with a github workflow and git tag

New Contributors

• @elvinpoole made their first contribution in #1

Full Changelog: v0.1.2...v0.2.0