fix requirement, test=doc

requirements.txt

@@ -45,3 +45,4 @@ visualdl
 webrtcvad
 yacs~=0.1.8
 yq
+zhon

setup.py

@@ -78,6 +78,7 @@ requirements = {
         "unidecode",
         "yq",
         "pre-commit",
+        "zhon",
     ]
 }