input: Write a python function to generate a list of unique random integers between 1 and 100.
  assert len(random_list(10)) == 10
  assert len(set(random_list(20))) == 20
  assert all(1 <= num <= 100 for num in random_list(15))
output: import random
  
  def random_list(n):
      return random.sample(range(1, 101), n)