Create function to form travel groups for all checkedin members of itinerary #176
Description
This use case is hyper-specific to the use case of Kitchener-Union Whatsapp. Everyone by default groups themselves based on departure and return time, and will do a poll where they join groups to buy tickets. E.g. whatsapp community is called transit-group-community-name, and then the chats are something like 7.16-9.13 to represent the departure and return trip. We will create a function that will look for all checked in members of the itinerary and group them if they have the same itinerary. Each group should have a steward. If the passengers exceed the number of stewards someone will be notified. The intention is for this function to be triggered about 20 minutes before the train arrives.