input: Write a python function to get numbers divisible by four within a given range.
  assert divisible_by_four(1, 10) == [4, 8]
  assert divisible_by_four(1, 16) == [4, 8, 12, 16]
  assert divisible_by_four(5, 20) == [8, 12, 16, 20]
output: def divisible_by_four(start, end):
      return [i for i in range(start, end + 1) if i % 4 == 0]