Introduce auger 'releases' for each kubernetes version

[jpbetz]

As @caesarxuchao pointed out to me, auger builds are paired specific kubernetes versions. Each auger build uses the types of exactly one kubernetes version, and the types supported change with each kubernetes version. So we should release auger versions in a way that clearly document which kubernetes versions they are for. A version scheme like 'auger--' might make the most sense. Ideally we would cross build auger against all currently supported kubernetes versions for each auger release and publish releases for all of these.

[caesarxuchao]

Thanks @jpbetz.

Maybe a single auger release can import schemas from multiple versions of Kubernetes, and dynamically select the schema based on a commandline flag.

[wangyx1992]

If I want to use auger with other kuberentes version such as 1.17.2, and etcd version like v3.4.3. What should I do with auger? Can you give me any suggestion？@jpbetz @caesarxuchao