input: Write a python function to sort a given list of numbers without using the built-in function sort().
  assert sort_list([4, 2, 9, 1, 5, 6]) == [1, 2, 4, 5, 6, 9]
  assert sort_list([10, -1, 3, 7, 0]) == [-1, 0, 3, 7, 10]
  assert sort_list([3, 3, 3, 3, 3]) == [3, 3, 3, 3, 3]
output: def sort_list(numbers):
      for i in range(len(numbers)):
          for j in range(0, len(numbers)-i-1):
              if numbers[j] > numbers[j+1]:
                  numbers[j], numbers[j+1] = numbers[j+1], numbers[j]
      return numbers