correct test data path

Author: mr-c

tests/test_parallel.py

@@ -20,7 +20,7 @@ def test_sequential_workflow(self):
         echo = f.make(get_data(test_file))
         self.assertEqual(echo(file1= {
                 "class": "File",
-                "location": "tests/wf/whale.txt"
+                "location": get_data("tests/wf/whale.txt")
             }),
             {"count_output": 16})