Add BUCK build script for graphitemetrics application

Change-Id: I9819eb183175b701aa7974a1d29be3cd62ff0be5
diff --git a/BUCK b/BUCK
index 825a17c..8359c45 100644
--- a/BUCK
+++ b/BUCK
@@ -93,6 +93,7 @@
     '//apps/iptopology-api:onos-app-iptopology-api',
     '//apps/metrics:onos-app-metrics',
     '//apps/gangliametrics:onos-app-ganglia',
+    '//apps/graphitemetrics:onos-app-graphite',
     '//apps/mfwd:onos-app-mfwd',
     '//apps/mlb:onos-app-mlb',
     '//apps/mobility:onos-app-mobility',