[ONOS-4481] Integrate scalable gateway to openstackRouting

 - Modified openstack_routing to use scalable gateway application
 - Add GatewayNode Builder method

Change-Id: Ib12d52009eeb89ab59f01cafe794894aac80985e
diff --git a/apps/openstacknetworking/openstackrouting/pom.xml b/apps/openstacknetworking/openstackrouting/pom.xml
index 4c6f638..3b74025 100644
--- a/apps/openstacknetworking/openstackrouting/pom.xml
+++ b/apps/openstacknetworking/openstackrouting/pom.xml
@@ -52,6 +52,11 @@
             <artifactId>onos-app-openstackinterface-api</artifactId>
             <version>${project.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-scalablegateway</artifactId>
+            <version>${project.version}</version>
+        </dependency>
     </dependencies>
 </project>