input: Write a python function to remove all zero values from a list.
  assert remove_zeros([0, 2, 3, 0, 4]) == [2, 3, 4]
  assert remove_zeros([0, 0, 0, 0]) == []
  assert remove_zeros([1, 2, 3, 4]) == [1, 2, 3, 4]
output: def remove_zeros(lst):
      return [x for x in lst if x != 0]