Change path for "Run one test" example in README.rst

Changed the reference from tempest.tests.compute... to
tempest.api.compute...

Fixes bug #1201039

Change-Id: I1bf925c47e73ecf6558ddb851b8178bd1f37f6f9
diff --git a/README.rst b/README.rst
index 992d19b..da0f5f3 100644
--- a/README.rst
+++ b/README.rst
@@ -40,7 +40,7 @@
     $> nosetests tempest
 
 To run one single test  ::
-    $> nosetests -sv tempest.tests.compute.servers.test_server_actions.py:
+    $> nosetests -sv tempest.api.compute.servers.test_server_actions.py:
        ServerActionsTestJSON.test_rebuild_nonexistent_server
 
 Configuration