fix: missing 2020-01-31

fix #73

fetch_holidays.py

@@ -189,6 +189,7 @@ class SentenceParser:
 
     special_cases = {
         '延长2020年春节假期至2月2日（农历正月初九': [
+            {"date": date(2020, 1, 31), "isOffDay": True},
             {"date": date(2020, 2, 1), "isOffDay": True},
             {"date": date(2020, 2, 2), "isOffDay": True},
         ],

tests/description_parsing_cases.json

@@ -3,6 +3,7 @@
     "year": 2020,
     "description": "延长2020年春节假期至2月2日（农历正月初九，星期日），2月3日（星期一）起正常上班。",
     "expected": [
+      { "date": "2020-01-31", "isOffDay": true },
       { "date": "2020-02-01", "isOffDay": true },
       { "date": "2020-02-02", "isOffDay": true },
       { "date": "2020-02-03", "isOffDay": false }