update read_camer.py to use urllib.parse or to fallback to older urlparse, update requirements to accept a higher version of opencv

Author: kurtfm

camera/read_camera.py

@@ -1,7 +1,10 @@
 import argparse
 import cv2
 import redis
-import urlparse
+try:
+    import urlparse
+except ImportError:
+    import urllib.parse as urlparse
 
 class Webcam:
     def __init__(self, infile=0, fps=15.0):

camera/requirements.txt

@@ -1,2 +1,2 @@
-opencv-python==4.0.1.23
+opencv-python<=4.0.1.23
 redis==3.2.1