Update ONOS version to 1.6.0-rc2

Change-Id: I429843d5dd2a5c6f8ff24ba8634848d45e782de7
diff --git a/.gitreview b/.gitreview
new file mode 100644
index 0000000..04597f0
--- /dev/null
+++ b/.gitreview
@@ -0,0 +1,6 @@
+[gerrit]
+host=gerrit.onosproject.org
+port=29418
+project=igmp.git
+defaultremote=origin
+defaultbranch=master