Change expected exception

Author: alexandresobolevski

Diff for: plotly/tests/test_core/test_file/test_file.py

@@ -49,7 +49,7 @@ def test_duplicate_folders(self):
         py.file_ops.mkdirs(first_folder)
         try:
             py.file_ops.mkdirs(first_folder)
-        except requests.exceptions.RequestException as e:
-            self.assertTrue(400 <= e.response.status_code < 500)
+        except PlotlyRequestError as e:
+            self.assertTrue(400 <= e.status_code < 500)
         else:
             self.fail('Expected this to fail!')