Updated published_date:

Changed it to unix timestamp

news/schema.py

@@ -59,8 +59,7 @@ class NewsArticleSchema(Schema):
     url = fields.URL(required=True, error_messages={'required': 'A NewsArticle must include a URL'})
     title = fields.Str()
     authors = fields.List(fields.Str())
-    # published_date = fields.DateTime()
+    published_date = UnixTimestamp()
-    published_date = PassDateTime()
     news_blob = fields.Str(required=True, error_messages={'required': 'NewsArticle must include news content'})
 
     # TODO add support for Tags