input: Write a python function to generate an array of random numbers between 0 and 1 using numpy.
  assert len(generate_random_numbers(10)) == 10
  assert all(0 <= num <= 1 for num in generate_random_numbers(100))
  assert isinstance(generate_random_numbers(5), np.ndarray)
output: def generate_random_numbers(n):
      import numpy as np
      return np.random.rand(n)