Extract CloudEvent code to it's own package

[mhoad]

I was wondering if you might be open to extracting the existing code you have around cloud events into it's own package. Given that it is both an open CNCF standard and it's the new default on GCS I think it is a reasonable expectation that this could be a useful standalone building block in the Dart community. Also if it is helpful to have a concrete use case I am currently playing around with another new CNCF project (Dapr) which involves receiving cloud events that would benefit from this.

[nickmeinhold]

I wonder if the CloudEvents SDK Requirements could be helpful?

The intent of this document to describe a minimum set of requirements for new Software Development Kits (SDKs) for CloudEvents