func GetRevisionFromSpec(spec *JobSpec) string {
	if spec.Refs != nil {
		return getRevisionFromRef(spec.Refs)
	} else if len(spec.ExtraRefs) > 0 {
		return getRevisionFromRef(&spec.ExtraRefs[0])
	}
	return ""
}
func GetRevisionFromSpec(spec *JobSpec) string {
	if spec.Refs != nil {
		return getRevisionFromRef(spec.Refs)
	} else if len(spec.ExtraRefs) > 0 {
		return getRevisionFromRef(&spec.ExtraRefs[0])
	}
	return ""
}
// GetRevisionFromSpec returns a main ref or sha from a spec object