This function is designed to parse the content returned by the interior
steps of the fare_estimate function.
parse_fare_estimate_content(fare_estimate_content)A data frame consisting of one row for each passenger_type, and the
following columns:
min_zone
max_zone
unique_zones
early_bird
free_tram_zone
weekend_journey
passenger_type
fare_2_hour_peak
fare_2_hour_off_peak
fare_daily_peak
fare_daily_off_peak
pass_7_days
pass_28_to_69_day_per_day
pass_70_plus_day_per_day
weekend_cap
holiday_cap
A direction, as a list, returned by the
fare_estimate API call.