Add a gui directory

Added an empty directory for deployment of gui files.
Amisha asked for this to make document how to deploy the ONOS
gui easier.

Change-Id: Id16a2042ef4bcb0e5db2d081c85befc98cf83e68
diff --git a/gui/.gitignore b/gui/.gitignore
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/gui/.gitignore