Does some tasks from #34

validation/warnings.json

@@ -4,15 +4,23 @@
             "user",
             "admin",
             "date",
-            "reason"
+            "reason",
+            "active",
+            "revoke_date"
         ],
         "properties": {
             "user": {
-                "bsonType": ["int", "long"],
+                "bsonType": [
+                    "int",
+                    "long"
+                ],
                 "description": "Telegram ID of user"
             },
             "admin": {
-                "bsonType": ["int", "long"],
+                "bsonType": [
+                    "int",
+                    "long"
+                ],
                 "description": "Telegram ID of admin"
             },
             "date": {
@@ -22,6 +30,17 @@
             "reason": {
                 "bsonType": "string",
                 "description": "Broken rule or admin's comment"
+            },
+            "active": {
+                "bsonType": "bool",
+                "description": "Whether warning is still present"
+            },
+            "revoke_date": {
+                "bsonType": [
+                    "date",
+                    "null"
+                ],
+                "description": "Date when warning got inactive"
             }
         }
     }