Add ability to pass a base test root and create results dirs relative.

bin/au_test_harness/dummy_au_worker.py

Index: bin/au_test_harness/dummy_au_worker.py
diff --git a/bin/au_test_harness/dummy_au_worker.py b/bin/au_test_harness/dummy_au_worker.py
index d16cd690f3c8ec41c1bc726d1442ea8cb8764a20..fa1bee042a5b37b9d3889fff6b2d9ffa7cf82860 100644
--- a/bin/au_test_harness/dummy_au_worker.py
+++ b/bin/au_test_harness/dummy_au_worker.py
@@ -18,8 +18,8 @@ class DummyAUWorker(au_worker.AUWorker):
   # Class variable that stores the list of payloads that would be needed.
   delta_list = {}
 
-  def __init__(self, options):
-    au_worker.AUWorker.__init__(self, options)
+  def __init__(self, options, test_results_root):
+    au_worker.AUWorker.__init__(self, options, test_results_root)
     self.au_type = options.type
 
   def PrepareBase(self, image_path):