Changed default accelerator

src/ptbench/scripts/train.py

@@ -181,7 +181,7 @@ def set_reproducible_cuda():
     help='A string indicating the accelerator to use (e.g. "auto", "cpu" or "gpu"). If auto, will select the best one available',
     show_default=True,
     required=True,
-    default="auto",
+    default="cpu",
     cls=ResourceOption,
 )
 @click.option(