Skip IOU test on Windows

Fix #159

tests/handlers/api/test_iou.py

@@ -18,10 +18,13 @@
 import pytest
 import os
 import stat
+import sys
 
 from tests.utils import asyncio_patch
 from unittest.mock import patch, MagicMock, PropertyMock
 
+pytestmark = pytest.mark.skipif(sys.platform.startswith("win"), reason="Not supported on Windows")
+
 
 @pytest.fixture
 def fake_iou_bin(tmpdir):