### tail

Returns all elements in an array except for the first one.

Return `arr.slice(1)` if the array's `length` is more than `1`, otherwise, return the whole array.

```js
const tail = arr => arr.length > 1 ? arr.slice(1) : arr;
```

```js
tail([1,2,3]) // [2,3]
tail([1]) // [1]
```