Fix testtools.run syntax for README.rst

Change-Id: I7762bc1954258eaa932239421a832fb7dc95d16e
Signed-off-by: Paul Belanger <pabelanger@redhat.com>
diff --git a/README.rst b/README.rst
index 84b9b7a..932edbf 100644
--- a/README.rst
+++ b/README.rst
@@ -118,7 +118,7 @@
   Construct a test to fully simulate the series of events you want to
   see, then run it in the foreground.  For example::
 
-    .tox/py27/bin/python -m testtools.run tests.test_scheduler.TestScheduler.test_jobs_executed
+    .tox/py27/bin/python -m testtools.run tests.unit.test_scheduler.TestScheduler.test_jobs_executed
 
   See TESTING.rst for more information.