run 'minikube delete' using sudo

Change-Id: I9c8e2945551f1a887ea4f3c4cb6d56f1cc184321
diff --git a/jjb/pipeline/chart-api-test-helm.groovy b/jjb/pipeline/chart-api-test-helm.groovy
index e8660fe..ed37ee9 100644
--- a/jjb/pipeline/chart-api-test-helm.groovy
+++ b/jjb/pipeline/chart-api-test-helm.groovy
@@ -261,7 +261,7 @@
            helm delete --purge "\${hchart}"
          done
 
-         minikube delete
+         sudo minikube delete
          '''
          step([$class: 'Mailer', notifyEveryUnstableBuild: true, recipients: "suchitra@opennetworking.org, you@opennetworking.org, kailash@opennetworking.org", sendToIndividuals: false])
     }