reporting a bug

[JmingZhang]

first, thank you for your great works. during my using of the program, i found a bug need to fix. But i am not familiar with R and also do not know how to update the code on github. the bug is that if you set all box to [1 1 1], which can full fill the container, then the ems_list is empty. A error is reported when the ems_list[i] is executed. it is easy to fix up the error by adding a code to the packBoxes.R as follow:

con_EMS <- packing_solution[[container_ind]][[1]]@ems if (isEmpty(ems_list)) {break; }
con_EMS <- PrioritizeEMS(con_EMS)