Dragging & dropping won't work since columns are also draggable. The complete UI collapses. <img width="947" alt="schermafbeelding_2017-11-30_om_15 37 24" src="https://user-images.githubusercontent.com/3257545/33436359-1370ca58-d5e5-11e7-81c7-4fa5a39c02c3.png">
