Add opencv dependency

requirements.txt

@@ -14,6 +14,7 @@ cma == 2.7.0
 sentencepiece
 nltk
 colorlog
+opencv-python
 
 # numpy no longer support python2 in version 1.17 and above
 numpy ; python_version >= "3"

setup.py

@@ -33,7 +33,7 @@ max_version, mid_version, min_version = python_version()
 REQUIRED_PACKAGES = [
     'six >= 1.10.0', 'protobuf >= 3.6.0', 'pyyaml', 'Pillow', 'requests',
     'tb-paddle', 'tensorboard >= 1.15', 'cma == 2.7.0', 'flask >= 1.1.0',
-    'sentencepiece', 'nltk', 'colorlog'
+    'sentencepiece', 'nltk', 'colorlog', 'opencv-python'
 ]
 
 if max_version < 3: