[PYTHON] Api doc python with multiple authentications (#928)

* [PYTHON] better code snippet for API usage with authentication

* update python samples

samples/client/petstore/python-tornado/docs/FakeApi.md

@@ -353,6 +353,8 @@ Fake endpoint for testing various parameters 假端點 偽のエンドポイン
 Fake endpoint for testing various parameters 假端點 偽のエンドポイント 가짜 엔드 포인트 
 
 ### Example
+
+* Basic Authentication (http_basic_test): 
 ```python
 from __future__ import print_function
 import time