CBLT-252:  use: submodule update --init --recursive

Change-Id: Ifa0a3a5a8856bd4fe24f5b4f58ae125e686616b1
Reviewed-on: http://review.couchbase.org/35126
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>