Adjust stress test documentation

Be more concrete about the stress test framework capabilities.

Change-Id: Ic331e47ffa0512179429176579f1e4a6caa82dfc
diff --git a/tempest/README.rst b/tempest/README.rst
index dbac809..18c7cf3 100644
--- a/tempest/README.rst
+++ b/tempest/README.rst
@@ -62,13 +62,10 @@
 stress
 ------
 
-Stress tests are designed to stress an OpenStack environment by
-running a high workload against it and seeing what breaks. Tools may
-be provided to help detect breaks (stack traces in the logs).
-
-TODO: old stress tests deleted, new_stress that david is working on
-moves into here.
-
+Stress tests are designed to stress an OpenStack environment by running a high
+workload against it and seeing what breaks. The stress test framework runs
+several test jobs in parallel and can run any existing test in Tempest as a
+stress job.
 
 thirdparty
 ----------