Fix return annotation of main in day01 and day02

I've inadvertently left the old annotation of `None` in place after
refactoring the way solutions are run. This commit rectifies that
mistake by changing it to `Tuple[int]`,

solutions/day01/solution.py

@@ -1,5 +1,5 @@
 import itertools
-from typing import List
+from typing import List, Tuple
 
 
 def _fuel_requirement(mass: int) -> int:
@@ -24,7 +24,7 @@ def part_two(data: List[int]) -> int:
     return sum(sum(itertools.takewhile(lambda fuel: fuel > 0, _module_fuel(mass))) for mass in data)
 
 
-def main(data: List[str]) -> None:
+def main(data: List[str]) -> Tuple[int]:
     data = [int(number) for number in data]
     answer_one = part_one(data)
     answer_two = part_two(data)

solutions/day02/solution.py

@@ -3,7 +3,7 @@
 import itertools
 import logging
 import operator
-from typing import Callable, List
+from typing import Callable, List, Tuple
 
 log = logging.getLogger(__name__)
 
@@ -47,7 +47,7 @@ def part_two(data: List[int]) -> int:
             return 100 * noun + verb
 
 
-def main(data: List[str]) -> None:
+def main(data: List[str]) -> Tuple[int]:
     """The main function taking care of parsing the input data and running the solutions."""
     op_codes = data[0].split(",")
     data = [int(number) for number in op_codes]