corrected folder creation error for MNLI-MM, verified GLUE results

examples/run_classifier.py

@@ -950,6 +950,11 @@ def main():
             task_name = "mnli-mm"
             processor = processors[task_name]()
 
+            if os.path.exists(args.output_dir + '-MM') and os.listdir(args.output_dir + '-MM') and args.do_train:
+                raise ValueError("Output directory ({}) already exists and is not empty.".format(args.output_dir))
+            if not os.path.exists(args.output_dir + '-MM'):
+                os.makedirs(args.output_dir + '-MM')
+
             eval_examples = processor.get_dev_examples(args.data_dir)
             eval_features = convert_examples_to_features(
                 eval_examples, label_list, args.max_seq_length, tokenizer, output_mode)