input: Write a function to sort a list of numbers using bubble sort.
  assert sort_numbers([5, 7, 1, 6, 10, 4, 2]) == [1, 2, 4, 5, 6, 7, 10]
  assert sort_numbers([3, 1, 4, 1, 5, 9, 2, 6, 5]) == [1, 1, 2, 3, 4, 5, 5, 6, 9]
  assert sort_numbers([10, 8, 2, 4, 7, 1, 5, 3, 9, 6]) == [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
output: def sort_numbers(numbers):
      n = len(numbers)
      for i in range(n):
          for j in range(0, n-i-1):
              if numbers[j] > numbers[j+1]:
                  numbers[j], numbers[j+1] = numbers[j+1], numbers[j]
      return numbers