Remove sys.version_info[0] == 2 or 3.

tests/test_optimization.py

@@ -15,11 +15,11 @@
 
 
 import os
+import tempfile
 import unittest
 
 from transformers import is_torch_available
 
-from .test_tokenization_common import TemporaryDirectory
 from .utils import require_torch
 
 
@@ -50,7 +50,7 @@ def unwrap_and_save_reload_schedule(scheduler, num_steps=10):
         scheduler.step()
         lrs.append(scheduler.get_lr())
         if step == num_steps // 2:
-            with TemporaryDirectory() as tmpdirname:
+            with tempfile.TemporaryDirectory() as tmpdirname:
                 file_name = os.path.join(tmpdirname, "schedule.bin")
                 torch.save(scheduler.state_dict(), file_name)