$ python start_app.py 
serving on http://127.0.0.1:8080


$ curl -H "X-Auth-Token:open-sesame"  http://127.0.0.1:8080
Hello, welccome to paste 


$ curl -H "X-Auth-Token:bad-token"  http://127.0.0.1:8080
<html>
 <head>
  <title>403 Forbidden</title>
 </head>
 <body>
  <h1>403 Forbidden</h1>
  Access was denied to this resource.<br /><br />
 </body>
</html>