fix issue #78
fix issue #78

drag-enter class isn't removed from the dragged element after the drag ends.
LSEducation/ngDraggable,brunokindt/ngDraggable,akveo/ngDraggable,minioak/ngDraggable,octaviandavid/ngDraggable,JIakki/ngDraggable,octaviandavid/ngDraggable,minioak/ngDraggable,Gmulti/ngDraggable,YellowSharkMT/ngDraggable,OdenFrey/ngDraggable,JIakki/ngDraggable,fatlinesofcode/ngDraggable,Gmulti/ngDraggable,fatlinesofcode/ngDraggable,lucaspenney/ngDraggable,beatboxjs/ngDraggable,lucaspenney/ngDraggable,OdenFrey/ngDraggable,gspinella/ngDraggable,LSEducation/ngDraggable,brunokindt/ngDraggable,magnet-clip/ngDraggable,dietrich-stein/ngDraggableRedux,akveo/ngDraggable,paschty/ngDraggable,magnet-clip/ngDraggable,YellowSharkMT/ngDraggable,gspinella/ngDraggable,endiny/ngDraggable,beatboxjs/ngDraggable,paschty/ngDraggable,endiny/ngDraggable,dietrich-stein/ngDraggableRedux