update kube and vendor dependencies

With kubernetes 1.18 release of client-go, signatures on methods in
generated clientsets, dynamic, metadata, and scale clients have been
modified to accept context.Context as a first argument.
Signatures of Create, Update, and Patch methods have been updated
to accept CreateOptions, UpdateOptions and PatchOptions respectively.
Signatures of Delete and DeleteCollection methods now accept
DeleteOptions by value instead of by reference.
These changes are now accommodated with this PR and client-go
and dependencies are updated to v1.18.0

Signed-off-by: Humble Chirammal <hchiramm@redhat.com>

vendor/k8s.io/kubernetes/pkg/util/slice/slice.go

@@ -19,8 +19,6 @@ package slice
 
 import (
 	"sort"
-
-	utilrand "k8s.io/apimachinery/pkg/util/rand"
 )
 
 // CopyStrings copies the contents of the specified string slice
@@ -41,20 +39,6 @@ func SortStrings(s []string) []string {
 	return s
 }
 
-// ShuffleStrings copies strings from the specified slice into a copy in random
-// order. It returns a new slice.
-func ShuffleStrings(s []string) []string {
-	if s == nil {
-		return nil
-	}
-	shuffled := make([]string, len(s))
-	perm := utilrand.Perm(len(s))
-	for i, j := range perm {
-		shuffled[j] = s[i]
-	}
-	return shuffled
-}
-
 // ContainsString checks if a given slice of strings contains the provided string.
 // If a modifier func is provided, it is called with the slice item before the comparation.
 func ContainsString(slice []string, s string, modifier func(s string) string) bool {