New test to verify ONOS cluster by restarting the same controller repeatedly.
Some changes to controllers_restart test.
Robot test entry for the single controller restart.

Change-Id: Idec493af3b7b7285bcfea424bb62c9a592470924
diff --git a/src/test/robot/cluster_controller.robot b/src/test/robot/cluster_controller.robot
index 6a2d0b6..61269ba 100644
--- a/src/test/robot/cluster_controller.robot
+++ b/src/test/robot/cluster_controller.robot
@@ -9,11 +9,16 @@
 ${EXTRA_OPTS}     -v
 
 *** Test Cases ***
-Verify Onos Controller Restart Functionality
+Verify Onos Controllers Restart Functionality
   [Documentation]  Verify ONOS cluster by restarting controllers iteratively
   ${rc}=  Run Cord Tester  cluster:cluster_exchange.test_cluster_controller_restarts
   Should Be Equal As Integers  ${rc}  0
 
+Verify Onos Single Controller Restart Functionality
+  [Documentation]  Verify ONOS cluster by restarting the same controller
+  ${rc}=  Run Cord Tester  cluster:cluster_exchange.test_cluster_single_controller_restarts
+  Should Be Equal As Integers  ${rc}  0
+
 *** Keywords ***
 Cord Cluster Setup
   [Documentation]  Configure a ${NODES} node ONOS cluster for cord tester