A implementation of Faster R-CNN with RoIAlign and ResNet50
reference from 'https://github.com/chenyuntc/simple-faster-rcnn-pytorch' and 'https://github.com/yfji/pytorch-faster-rcnn'
use 'python3 build.py build_ext --inplace' to build nms
use './make.sh' to build roi_align
train on voc2007 and coco2017