Support for horizontal list?

I have a horizontal list to sort, after adding `horizontal={true}` to the sortable list, I observed the sorting behavior is weird, and I still have to drag the item up and down.

Here's example:
````
{
order.splice(e.to, 0, order.splice(e.from, 1)[0])
this.forceUpdate()
}}
horizontal={true} <------ added this to make it horizontal.
renderRow={row => }
/>
````

Any suggested work around? Thanks.