input: Write a function that subtracts elements of two lists using map and lambda. 
  assert sub_list([1, 2, 3],[4,5,6])==[-3,-3,-3]
  assert sub_list([1,2],[3,4])==[-2,-2]
  assert sub_list([90,120],[50,70])==[40,50]
output: def sub_list(list1, list2):
      return list(map(lambda x, y: x - y, list1, list2))