Use mattermost v5 module (#1192)

vendor/github.com/mattermost/mattermost-server/v5/model/file.go

@@ -0,0 +1,34 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+import (
+	"encoding/json"
+	"io"
+)
+
+const (
+	MaxImageSize = int64(6048 * 4032) // 24 megapixels, roughly 36MB as a raw image
+)
+
+var (
+	IMAGE_EXTENSIONS = [7]string{".jpg", ".jpeg", ".gif", ".bmp", ".png", ".tiff", "tif"}
+	IMAGE_MIME_TYPES = map[string]string{".jpg": "image/jpeg", ".jpeg": "image/jpeg", ".gif": "image/gif", ".bmp": "image/bmp", ".png": "image/png", ".tiff": "image/tiff", ".tif": "image/tif"}
+)
+
+type FileUploadResponse struct {
+	FileInfos []*FileInfo `json:"file_infos"`
+	ClientIds []string    `json:"client_ids"`
+}
+
+func FileUploadResponseFromJson(data io.Reader) *FileUploadResponse {
+	var o *FileUploadResponse
+	json.NewDecoder(data).Decode(&o)
+	return o
+}
+
+func (o *FileUploadResponse) ToJson() string {
+	b, _ := json.Marshal(o)
+	return string(b)
+}