enabling dumb-init for shovel

Change-Id: I6bb546c21866f4b6d8f1095079f288945080396d
diff --git a/compose/docker-compose-system-test.yml b/compose/docker-compose-system-test.yml
index 344f6f9..84a8dd2 100644
--- a/compose/docker-compose-system-test.yml
+++ b/compose/docker-compose-system-test.yml
@@ -105,6 +105,7 @@
     - consul
     - kafka
     - grafana
+    restart: unless-stopped
 
   #
   # Voltha server instance(s)