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