revise transform and pascalvoc dataset

demo/detection/yolov3_darknet53_pascalvoc/predict.py

@@ -4,6 +4,6 @@ import paddlehub as hub
 if __name__ == '__main__':
     place = paddle.CUDAPlace(0)
     paddle.disable_static()
-    model = model = hub.Module(name='yolov3_darknet53_pascalvoc', is_train=False)
+    model = hub.Module(name='yolov3_darknet53_pascalvoc', is_train=False)
     model.eval()
     model.predict(imgpath="4026.jpeg", filelist="/PATH/TO/JSON/FILE")

paddlehub/datasets/pascalvoc.py

@@ -22,8 +22,6 @@ import numpy as np
 from paddlehub.env import DATA_HOME
 from pycocotools.coco import COCO
 
-from paddlehub.process.transforms import DetectCatagory, ParseImages
-
 
 class DetectCatagory:
     """Load label name, id and map from detection dataset.