Use mod vendor for vendored directory (backwards compatible)

vendor/github.com/mattermost/mattermost-server/model/security_bulletin.go

@@ -1,41 +0,0 @@
-// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
-// See License.txt for license information.
-
-package model
-
-import (
-	"encoding/json"
-	"io"
-)
-
-type SecurityBulletin struct {
-	Id               string `json:"id"`
-	AppliesToVersion string `json:"applies_to_version"`
-}
-
-type SecurityBulletins []SecurityBulletin
-
-func (me *SecurityBulletin) ToJson() string {
-	b, _ := json.Marshal(me)
-	return string(b)
-}
-
-func SecurityBulletinFromJson(data io.Reader) *SecurityBulletin {
-	var o *SecurityBulletin
-	json.NewDecoder(data).Decode(&o)
-	return o
-}
-
-func (me SecurityBulletins) ToJson() string {
-	if b, err := json.Marshal(me); err != nil {
-		return "[]"
-	} else {
-		return string(b)
-	}
-}
-
-func SecurityBulletinsFromJson(data io.Reader) SecurityBulletins {
-	var o SecurityBulletins
-	json.NewDecoder(data).Decode(&o)
-	return o
-}