Added test code to test the flow subsystem performance

Change-Id: I1a7c68492760a63b7d092c3ca71e4964123c8aa7
diff --git a/apps/demo/pom.xml b/apps/demo/pom.xml
index e78ad3b..e66ccc2 100644
--- a/apps/demo/pom.xml
+++ b/apps/demo/pom.xml
@@ -106,6 +106,7 @@
                             com.sun.jersey.server.impl.container.servlet,
                             com.fasterxml.jackson.databind,
                             com.fasterxml.jackson.databind.node,
+                            org.apache.commons.lang.math.*,
                             com.google.common.*,
                             org.onlab.packet.*,
                             org.onlab.rest.*,