Added warning that it takes upto 10 minutes for changes to reflect
Added warning that it takes upto 10 minutes for changes to reflect

jaduimstra/nilmtk,mmottahedi/nilmtk,nilmtk/nilmtk,HarllanAndrye/nilmtk,pauldeng/nilmtk,josemao/nilmtk,AlexRobson/nilmtk,nilmtk/nilmtk