input: Write a function called `chatbot_response` that takes a user's input as a string and returns a randomly selected response from a predefined list of answers. The function should be part of a simple chatbot that interacts with the user in a loop, responding to any input until the user types 'Goodbye'. If the user types 'Goodbye', the chatbot should respond with 'Goodbye!' and terminate the loop.
  assert chatbot_response("What's your favorite color?") in ["That's a great question!", "I'm not sure, but I'll try to find out!", "That sounds interesting, tell me more!", "I have no idea, sorry!"]
  assert chatbot_response("Do you like pizza?") in ["That's a great question!", "I'm not sure, but I'll try to find out!", "That sounds interesting, tell me more!", "I have no idea, sorry!"]
output: def chatbot_response(user_input):
      if user_input == 'Goodbye':
          return 'Goodbye!'
      responses = ["That's a great question!", "I'm not sure, but I'll try to find out!", "That sounds interesting, tell me more!", "I have no idea, sorry!"]
      return random.choice(responses)