Add DNS RFC 1035 label format validator

[0n1shi]

Enhances

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• Tests exist or have been written that cover this particular change.

Change details:

• Add DNS RFC 1035 label validation based on RFC 1035

@go-playground/validator-maintainers

[coveralls]

Coverage increased (+0.01%) to 75.11% when pulling 06ef82a on 0n1shi:dns_rfc1035 into ce34f36 on go-playground:master.

[deankarn]

Why close @0n1shi ?

[0n1shi]

Is this too niche ? only label.

I wanted to use this like below
https://github.com/kubernetes/kubernetes/blob/HEAD/staging/src/k8s.io/apimachinery/pkg/util/validation/validation.go#L219

for providing app hosting service on kubernetes.

[deankarn]

The PR works for me. I just have very little time to merge and maintain recently.

[0n1shi]

Sorry for bothering you while you're busy.

I recreated the same PR below.
#833

You can close it if you dont need it :)