User can delete a stop

https://trello.com/c/LEt5Jtvi/44-as-a-user-i-can-delete-a-stop

![delete a stop](https://cloud.githubusercontent.com/assets/3759510/5111323/8ea84d2e-6fed-11e4-9c26-2c873dc5f05f.gif)
`in_order` rather than `asc_order`?