added required dependencies

app.py

@@ -5,6 +5,8 @@ import layoutparser as lp
 from PIL import Image
 import PIL
 
+os.system('pip install "git+https://github.com/facebookresearch/detectron2.git@v0.4#egg=detectron2" ')
+
 model = lp.Detectron2LayoutModel('lp://PubLayNet/faster_rcnn_R_50_FPN_3x/config', 
                                  extra_config=["MODEL.ROI_HEADS.SCORE_THRESH_TEST", 0.8],
                                  label_map={0: "Text", 1: "Title", 2: "List", 3:"Table", 4:"Figure"})

requirements.txt

@@ -1,3 +1,5 @@
 layoutparser
-git+https://github.com/facebookresearch/detectron2.git@v0.4#egg=detectron2
-layoutparser[ocr]
+layoutparser[ocr]
+torch
+torchvision
+torchaudio