Template files for the assignment of section 1.
Implemented 1.01: is_older
Implemented 1.02: number_in_month
Implemented 1.03: number_in_months
implemented 1.04: date_in_month and 1.05: date_in_months
Implemented 1.06: get_nth
Implemented 1.07: date_to_string
Implemented 1.08: number_before_reaching_sum
Implemented 1.09: what_month
Implemented 1.10: month_range
Implemented 1.11: oldest