Update go dependencies

vendor/k8s.io/client-go/tools/clientcmd/client_config.go

@@ -35,7 +35,7 @@ import (
 var (
 	// ClusterDefaults has the same behavior as the old EnvVar and DefaultCluster fields
 	// DEPRECATED will be replaced
-	ClusterDefaults = clientcmdapi.Cluster{Server: os.Getenv("KUBERNETES_MASTER")}
+	ClusterDefaults = clientcmdapi.Cluster{Server: getDefaultServer()}
 	// DefaultClientConfig represents the legacy behavior of this package for defaulting
 	// DEPRECATED will be replace
 	DefaultClientConfig = DirectClientConfig{*clientcmdapi.NewConfig(), "", &ConfigOverrides{
@@ -43,6 +43,15 @@ var (
 	}, nil, NewDefaultClientConfigLoadingRules(), promptedCredentials{}}
 )
 
+// getDefaultServer returns a default setting for DefaultClientConfig
+// DEPRECATED
+func getDefaultServer() string {
+	if server := os.Getenv("KUBERNETES_MASTER"); len(server) > 0 {
+		return server
+	}
+	return "http://localhost:8080"
+}
+
 // ClientConfig is used to make it easy to get an api server client
 type ClientConfig interface {
 	// RawConfig returns the merged result of all overrides