Update app.py

app.py

@@ -18,8 +18,8 @@ User should upload a landscape image with the Pokemon card image positioned upri
 """
 import os
 
-os.system('apt-get update && apt-get install -y python3-opencv')
-os.system('pip install opencv-python')
+RUN apt-get update && apt-get install -y python3-opencv
+RUN pip install opencv-python
 import cv2
 from PIL import Image
 import tensorflow as tf