[deviantart] always download original images

Deviation-objects returned by the DeviantArt API don't always contain
the URL and metadata of the original image ([1]). Getting this
information requires an additional API call [2], which is indicated by
the 'is_downloadable' and 'download_filesize' metadata within a
deviation-object.

[1] https://myria-moon.deviantart.com/art/Aime-Moi-part-en-vadrouille-261986576
[2] https://www.deviantart.com/developers/http/v1/20160316/deviation_download/bed6982b88949bdb08b52cd6763fcafd

test/test_extractors.py

@@ -27,17 +27,23 @@ class TestExtractors(unittest.TestCase):
         config.clear()
 
     def _run_test(self, extr, url, result):
-        content = "content" in result if result else False
+        if result:
+            if "options" in result:
+                for key, value in result["options"]:
+                    config.set(key.split("."), value)
+            content = "content" in result
+        else:
+            content = False
+
         tjob = job.TestJob(url, content=content)
         self.assertEqual(extr, tjob.extractor.__class__)
+
         if not result:
             return
-        if "options" in result:
-            for key, value in result["options"]:
-                config.set(key, value)
         if "exception" in result:
             self.assertRaises(result["exception"], tjob.run)
             return
+
         tjob.run()
         if "url" in result:
             self.assertEqual(result["url"], tjob.hash_url.hexdigest())