feat: add azure storage support (#735)

* feat: add zure storage support

* Update local_file_system.go

Co-authored-by: Gucheng <85475922+nomeguy@users.noreply.github.com>

storage/azure.go

@@ -0,0 +1,31 @@
+// Copyright 2021 The Casdoor Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package storage
+
+import (
+	"github.com/casdoor/oss"
+	"github.com/casdoor/oss/azureblob"
+)
+
+func NewAzureBlobStorageProvider(clientId string, clientSecret string, region string, bucket string, endpoint string) oss.StorageInterface {
+	sp := azureblob.New(&azureblob.Config{
+		AccessId:  clientId,
+		AccessKey: clientSecret,
+		Region:    region,
+		Bucket:    bucket,
+		Endpoint:  endpoint,
+	})
+	return sp
+}