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Build Kubernetes binaries with valid Semantic Version
**What this PR does / why we need it**:
Refuse to build Kubernetes when a version string like `v1.8.3+xx+xx`.
This PR is to restrict the `KUBE_GIT_VERSION`, if the version string does match the rule of Semantic Version, then refuse to build.
Since Kubernetes Conformance test needs the `KUBE_GIT_VERSION` to be a valid Semantic Version, so I think it's better to restrict the version string.
**Release note**:
```release-note
NONE
```
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