update README, fix model folder name

Author: foamliu

README.md

@@ -28,7 +28,7 @@ $ wget --no-check-certificate https://ai.stanford.edu/~jkrause/cars/car_devkit.t
 
 ## ImageNet Pretrained Models
 
-Download [ResNet-152](https://drive.google.com/file/d/0Byy2AcGyEVxfeXExMzNNOHpEODg/view?usp=sharing) into imagenet_models folder.
+Download [ResNet-152](https://drive.google.com/file/d/0Byy2AcGyEVxfeXExMzNNOHpEODg/view?usp=sharing) into models folder.
 
 ## Usage