Small change allowing dragula.js to work in iframe environments
Small change allowing dragula.js to work in iframe environments

See problem here: https://github.com/bevacqua/angular-dragula/issues/47

fixes bevacqua/angular-dragula#45
bevacqua/dragula,jimf/dragula,luckylooke/dragon,jaw4ik/dragula,rlugojr/dragula,linearza/dragula,jimf/dragula,looker/dragula,rwillbrown/dragula,linearza/dragula,rlugojr/dragula,rwillbrown/dragula,luckylooke/dragon,sherbrow/dragula,sherbrow/dragula,bevacqua/dragula,looker/dragula,jaw4ik/dragula