input: Write a function to convert a list of temperatures from Celsius to Fahrenheit.
  assert celsius_to_fahrenheit([21, 12, -4]) == [69.8, 53.6, 24.8]
  assert celsius_to_fahrenheit([0, 100, -40]) == [32.0, 212.0, -40.0]
  assert celsius_to_fahrenheit([-30, 0, 30]) == [-22.0, 32.0, 86.0]
output: def celsius_to_fahrenheit(celsius_list):
      return [(temp * 9/5) + 32 for temp in celsius_list]