adding test to check that warning is printed when default Docker container is used on windows

Author: kapilkd13

tests/test_docker_warning.py

@@ -0,0 +1,25 @@
+from __future__ import absolute_import
+import unittest
+from mock import mock
+from cwltool.utils import windows_default_container_id
+from cwltool.draft2tool import DEFAULT_CONTAINER_MSG, CommandLineTool
+
+
+class TestDefaultDockerWarning(unittest.TestCase):
+
+    # Test to check warning when default docker Container is used on Windows
+    @mock.patch("cwltool.draft2tool.onWindows",return_value = True)
+    @mock.patch("cwltool.draft2tool._logger")
+    def test_default_docker_warning(self,mock_logger,mock_windows):
+
+        class TestCommandLineTool(CommandLineTool):
+            def __init__(self, **kwargs):
+                self.requirements=[]
+                self.hints=[]
+
+            def find_default_container(args, builder):
+                return windows_default_container_id
+
+        TestObject = TestCommandLineTool()
+        TestObject.makeJobRunner()
+        mock_logger.warning.assert_called_with(DEFAULT_CONTAINER_MSG%(windows_default_container_id, windows_default_container_id))