Adjusted calculate_rating function to better calculate zero votes, and zero upvotes with downvotes
Each vote recalculates a checkins calculated_rating
User rating updates with votes
Only set's average_rating if there is a user assocaited with a checkin
Fixed bug where markers didn't show unless every attraction in the list had a checkin
Added att_type to attractions. Fixed get_markes when there is no checkin_id for an attraction
Added custom icon for food truck
Adding truck image file