2、随机打乱数组项的排列顺序

mockjs shuffle

官网示例：
// Random.shuffle( arr )
Random.shuffle(['a', 'e', 'i', 'o', 'u'])
Mock.mock('@shuffle(["a", "e", "i", "o", "u"])')

结果：
// Random.shuffle( arr )
["a","o","i","u","e"]
["i","o","u","a","e"]