Adds the transfer of sentiments into the sql db (#253)

Transfers the sentimenes from the mongodb int the sql db.

tests/models/news_test.py

@@ -20,4 +20,6 @@ def test_to_dict() -> None:
         "date": news.date,
         "text": news.text,
         "source_url": news.source_url,
+        "sentiment": None,
+        "companies": None,
     }