Revert "uncomment _source_authors line"

This reverts commit 89ce26a8.

src/ISTEX/Client.hs

@@ -27,7 +27,7 @@ instance FromJSON Author where
 
 data Source = Source
   { _source_title           :: Maybe T.Text
-  , _source_authors         :: [Author]
+  -- , _source_authors         :: [Author]
   , _source_publicationDate :: Maybe Int
   } deriving (Show, Generic)
 L.makeLenses ''Source
@@ -44,7 +44,7 @@ parsePubDate (Just pubDate) =
 instance FromJSON Source where
   parseJSON (Object o) = do
     _source_title     <- o .:? "title"
-    _source_authors <- o .:? "author"
+    -- _source_authors <- o .:? "author"
     mPubDate        <- o .:? "publicationDate"
 
     pure $ Source { _source_publicationDate = parsePubDate mPubDate