Add license headers and .gitreview file

Change-Id: Ia658a979c73175948944d249641e455cdb90c2a8
diff --git a/.gitreview b/.gitreview
new file mode 100644
index 0000000..c70a26b
--- /dev/null
+++ b/.gitreview
@@ -0,0 +1,5 @@
+[gerrit]
+host=gerrit.opencord.org
+port=29418
+project=voltha-go.git
+defaultremote=origin