user_query: No I want to add milk, bread, lunch meat to shopping list
response_text: Alright, I added those two things.
user_query: I want to add milk, bread, lunch meat to shopping list 
response_text: Alright, I added those two things.
User: Cancel that 2pm ride to San Francisco.
Parse: Cancel_ride ( dropoff_location « San Francisco » pickup_time « 2pm » )