Add cpu for backward done.  You can download here

https://www.mediafire.com/file/ehhg3r2hxe8yb8j/faster_rcnn.tar.xz
1. fixed warning in pytorch
2. install_data.sh will prepare all package install and cpp build
3. python3 ./train.py --dataset voc2007 --backbone resnet101 --cuda True
4. python3 ./train.py --dataset voc2007 --backbone resnet101   
step 4 is for cpu - test ok

by Jesse Stone