Update vendor (github.com/mattermost)

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

@@ -0,0 +1,59 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package model
+
+import (
+	"fmt"
+)
+
+type SlackAttachment struct {
+	Id         int64                   `json:"id"`
+	Fallback   string                  `json:"fallback"`
+	Color      string                  `json:"color"`
+	Pretext    string                  `json:"pretext"`
+	AuthorName string                  `json:"author_name"`
+	AuthorLink string                  `json:"author_link"`
+	AuthorIcon string                  `json:"author_icon"`
+	Title      string                  `json:"title"`
+	TitleLink  string                  `json:"title_link"`
+	Text       string                  `json:"text"`
+	Fields     []*SlackAttachmentField `json:"fields"`
+	ImageURL   string                  `json:"image_url"`
+	ThumbURL   string                  `json:"thumb_url"`
+	Footer     string                  `json:"footer"`
+	FooterIcon string                  `json:"footer_icon"`
+	Timestamp  interface{}             `json:"ts"` // This is either a string or an int64
+	Actions    []*PostAction           `json:"actions,omitempty"`
+}
+
+type SlackAttachmentField struct {
+	Title string      `json:"title"`
+	Value interface{} `json:"value"`
+	Short bool        `json:"short"`
+}
+
+func StringifySlackFieldValue(a []*SlackAttachment) []*SlackAttachment {
+	var nonNilAttachments []*SlackAttachment
+	for _, attachment := range a {
+		if attachment == nil {
+			continue
+		}
+		nonNilAttachments = append(nonNilAttachments, attachment)
+
+		var nonNilFields []*SlackAttachmentField
+		for _, field := range attachment.Fields {
+			if field == nil {
+				continue
+			}
+			nonNilFields = append(nonNilFields, field)
+
+			if field.Value != nil {
+				// Ensure the value is set to a string if it is set
+				field.Value = fmt.Sprintf("%v", field.Value)
+			}
+		}
+		attachment.Fields = nonNilFields
+	}
+	return nonNilAttachments
+}