input: Write a python function to generate a random integer between two given values.
  assert 1 <= random_int(1, 10) <= 10
  assert 50 <= random_int(50, 100) <= 100
  assert 0 <= random_int(0, 0) <= 0
output: import random
  
  def random_int(a, b):
      return random.randint(a, b)