Skip IOU test on Windows

Fix #159

gns3server/modules/__init__.py

@@ -25,6 +25,8 @@ from .qemu import Qemu
 MODULES = [VPCS, VirtualBox, Dynamips, Qemu]
 
 if sys.platform.startswith("linux") or hasattr(sys, "_called_from_test") or os.environ.get("PYTEST_BUILD_DOCUMENTATION") == "1":
-    # IOU runs only on Linux
-    from .iou import IOU
-    MODULES.append(IOU)
+
+    # IOU runs only on Linux but testsuite work on UNIX platform
+    if not sys.platform.startswith("win"):
+        from .iou import IOU
+        MODULES.append(IOU)