List examples function doesn't accept arguments

Change-Id: Ic8d9e5b8918dd47190d7aa3b6cfbe281307fb1d2

taskflow/tests/test_examples.py

@@ -112,7 +112,7 @@ ExamplesTestCase.update()
 
 def make_output_files():
     """Generate output files for all examples"""
-    for name in list_examples(False):
+    for name in list_examples():
         output = run_example(name)
         with open(expected_output_path(name), 'w') as f:
             f.write(output)