Added BMv2 demo apps (onos1.6 cherry-pick)

Change-Id: I19484a826acce724c1fcd5b6e9910d724bda686f
diff --git a/apps/pom.xml b/apps/pom.xml
index a8ba456..6da2972 100644
--- a/apps/pom.xml
+++ b/apps/pom.xml
@@ -71,6 +71,7 @@
         <module>graphitemetrics</module>
         <module>xosclient</module>
         <module>scalablegateway</module>
+        <module>bmv2-demo</module>
     </modules>