input: Write a python function to find the index of an item in a list.
  assert findIndex([1, 2, 3, 4, 5], 4) == 3
  assert findIndex([10, 20, 30, 40, 50], 30) == 2
  assert findIndex(['a', 'b', 'c', 'd'], 'd') == 3
output: def findIndex(lst, item):
      return lst.index(item)