input: Write a python function to generate a list of n random integers between 0 and 9.
  assert len(random_array(5))==5
  assert len(random_array(10))==10
  assert all(0 <= x <= 9 for x in random_array(15))
  assert type(random_array(3)) == list
output: import random
  
  def random_array(n):
      return [random.randint(0, 9) for _ in range(n)]