CORD-2772 set version number for vrouter service

Change-Id: I7bbf4150c7529e97c7d3a8c1571a50b456f27662
diff --git a/VERSION b/VERSION
new file mode 100644
index 0000000..3f6d5ce
--- /dev/null
+++ b/VERSION
@@ -0,0 +1 @@
+6.0.0.dev0