Update go dependencies

vendor/github.com/go-openapi/spec/ref.go

@@ -15,8 +15,6 @@
 package spec
 
 import (
-	"bytes"
-	"encoding/gob"
 	"encoding/json"
 	"net/http"
 	"os"
@@ -150,28 +148,6 @@ func (r *Ref) UnmarshalJSON(d []byte) error {
 	return r.fromMap(v)
 }
 
-// GobEncode provides a safe gob encoder for Ref
-func (r Ref) GobEncode() ([]byte, error) {
-	var b bytes.Buffer
-	raw, err := r.MarshalJSON()
-	if err != nil {
-		return nil, err
-	}
-	err = gob.NewEncoder(&b).Encode(raw)
-	return b.Bytes(), err
-}
-
-// GobDecode provides a safe gob decoder for Ref
-func (r *Ref) GobDecode(b []byte) error {
-	var raw []byte
-	buf := bytes.NewBuffer(b)
-	err := gob.NewDecoder(buf).Decode(&raw)
-	if err != nil {
-		return err
-	}
-	return json.Unmarshal(raw, r)
-}
-
 func (r *Ref) fromMap(v map[string]interface{}) error {
 	if v == nil {
 		return nil