Promote spec to beta

[sftim]

At the moment, the release status of the CNI specification is unclear (see discussion about removing the existing alpha warning for Kubernetes documentation and for the kubelet).

https://github.com/containernetworking/cni/blob/master/SPEC.md#version lists the version, at the time of writing, as 0.4.0, which suggests the possibility of breaking changes between now and a future stable release.

I recommend officially bumping the specification to beta and announcing that bump.

[sftim]

Motivation / background, as I see it:

• people are a lot more comfortable using things labelled beta
• some firms have a policy of not using Kubernetes alpha APIs, though how they get their Pods to talk to anything I don't know
• CRI is taking a similar approach; see https://docs.google.com/document/d/1xMfiVUX4lF0G6Y_yQ4l-5-wrOneeJWcXY2NGVGuTdH8/

BTW, happy to move this discussion to an issue in the CNI repo.

[sftim]

Slightly related to #783 and #771

[bboreham]

the possibility of breaking changes between now and a future stable release.

#771 lists breaking changes we intend to make before 1.0.

BTW, happy to move this discussion to an issue in the CNI repo.

This is an issue in the CNI repo; please explain.

[sftim]

BTW, happy to move this discussion to an issue in the CNI repo.

D'oh.

[dcbw]

We have released 1.0 and it is no longer beta.