update invalid input check

chatbot_simulator.py

@@ -25,6 +25,7 @@ class ChatbotSimulation:
         self.user_state = dict()
         self.user_state['current_page'] = self.sitemap['pages'][0]['id']  # Initialize current page
         self.user_state['task_completed'] = 'False'
+        self.user_state['logged_in'] = 'False'
         self.user_state['back'] = 'False'
 
         self.log_location = log_location