Put license header in shared file

samples/client/petstore/python/setup.py

@@ -1,5 +1,21 @@
 # coding: utf-8
 
+"""
+   Copyright 2016 SmartBear Software
+
+   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.
+"""
+
 import sys
 from setuptools import setup, find_packages