Support ditributed testing with torch.distributed.launch (#114)

* add dist_test.sh script for multi-gpu testing

* update README.md

docs/GETTING_STARTED.md

@@ -19,6 +19,12 @@ python test.py --cfg_file ${CONFIG_FILE} --batch_size ${BATCH_SIZE} --eval_all
 ```shell script
 sh scripts/slurm_test_mgpu.sh ${PARTITION} ${NUM_GPUS} \ 
     --cfg_file ${CONFIG_FILE} --batch_size ${BATCH_SIZE}
+
+# or
+
+sh scripts/dist_test.sh ${NUM_GPUS} \
+    --cfg_file ${CONFIG_FILE} --batch_size ${BATCH_SIZE}
+
 ```
 
 

tools/scripts/dist_test.sh

+#!/usr/bin/env bash
+
+set -x
+NGPUS=$1
+PY_ARGS=${@:2}
+
+python -m torch.distributed.launch --nproc_per_node=${NGPUS} test.py --launcher pytorch ${PY_ARGS}
+