fix packaging and imports and introduce tests with pytest.

still issues with celery worker.

application/parser/file/base.py

@@ -3,7 +3,7 @@ from abc import abstractmethod
 from typing import Any, List
 
 from langchain.docstore.document import Document as LCDocument
-from parser.schema.base import Document
+from application.parser.schema.base import Document
 
 
 class BaseReader: