remove go-openapi/spec

Signed-off-by: Gautier Delorme <gautier.delorme@gmail.com>

Kubernetes-commit: 34b0fcef5fc47e3fcddf7f6ca1b3e6176b2a5323

Author: gautierdelorme

go.mod

@@ -15,7 +15,6 @@ require (
 	github.com/fatih/camelcase v1.0.0
 	github.com/fsnotify/fsnotify v1.4.9 // indirect
 	github.com/fvbommel/sortorder v1.0.1
-	github.com/go-openapi/spec v0.19.5
 	github.com/golangplus/testing v0.0.0-20180327235837-af21d9c3145e // indirect
 	github.com/google/go-cmp v0.5.2
 	github.com/googleapis/gnostic v0.5.1

pkg/util/openapi/extensions.go

@@ -16,7 +16,7 @@ limitations under the License.
 
 package openapi
 
-import "github.com/go-openapi/spec"
+import "k8s.io/kube-openapi/pkg/validation/spec"
 
 // PrintColumnsKey is the key that defines which columns should be printed
 const PrintColumnsKey = "x-kubernetes-print-columns"