old_contents: from pigeon import app
  app.run(debug=app.config.get('DEBUG', False), host='0.0.0.0', port=5654)
  
new_contents: #!/usr/bin/env python
  
  from pigeon import app
  app.run(debug=app.config.get('DEBUG', False),
          host='0.0.0.0',
          port=5654)
  
subject: add shebang to runpigeon