add mutil_task training script
add mutil_task training script

likelyzhao/mxnet,likelyzhao/mxnet,likelyzhao/mxnet,likelyzhao/mxnet,likelyzhao/mxnet,likelyzhao/mxnet,likelyzhao/mxnet,likelyzhao/mxnet,likelyzhao/mxnet