Bump OpenCV version

Edouard Belval · Edouard Belval · commit 6da71595e445 · 2019-02-27T19:42:48.000-05:00
diff --git a/requirements.txt b/requirements.txt
@@ -1,6 +1,6 @@
 beautifulsoup4==4.6.0
 numpy==1.15.1
-opencv-python==3.4.3.18
+opencv-python==4.0.0.21
 tqdm==4.23.4
 Pillow==5.1.0
 requests==2.20.0
