Update vendor (github.com/mattermost)

vendor/github.com/mattermost/mattermost-server/einterfaces/saml.go

@@ -0,0 +1,15 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package einterfaces
+
+import (
+	"github.com/mattermost/mattermost-server/model"
+)
+
+type SamlInterface interface {
+	ConfigureSP() *model.AppError
+	BuildRequest(relayState string) (*model.SamlAuthRequest, *model.AppError)
+	DoLogin(encodedXML string, relayState map[string]string) (*model.User, *model.AppError)
+	GetMetadata() (string, *model.AppError)
+}