Fixed json encoder for objects not using pydantic

jeeves/core/parsers.py

@@ -1,4 +1,3 @@
-import json
 from typing import Any, Text, MutableMapping
 from pathlib import Path
 
@@ -33,7 +32,7 @@ class ObjectParser:
 
     @classmethod
     def to_json(cls, obj: BaseObject) -> Text:
-        return json.dumps(cls.to_dict(obj))
+        return obj.json()
 
     @classmethod
     def from_toml(cls, serialized: Text) -> BaseObject: