Use versioned virtualenv for virtualenv_wrapper

BUG=chromium:703769
TEST=Run virtualenv’ed unittests

Change-Id: I84834ebca61b0caf7ae99c0cd8aa070ca2b32365
Reviewed-on: https://chromium-review.googlesource.com/461380
Tested-by: Allen Li <ayatane@chromium.org>
Reviewed-by: Allen Li <ayatane@chromium.org>
Commit-Queue: Allen Li <ayatane@chromium.org>
Trybot-Ready: Allen Li <ayatane@chromium.org>
diff --git a/scripts/virtualenv_wrapper_unittest.py b/scripts/virtualenv_wrapper_unittest.py
index af07d91..e1efe58 100644
--- a/scripts/virtualenv_wrapper_unittest.py
+++ b/scripts/virtualenv_wrapper_unittest.py
@@ -26,7 +26,7 @@
     # be provided inside the chromite virtualenv.
     six = __import__('six')
     req_path = os.path.dirname(os.path.realpath(six.__file__))
-    self.assertIn(virtualenv_wrapper._VENV_DIR, req_path)
+    self.assertIn('/.cache/cros_venv/', req_path)
 
 
   def testInsideVenv(self):