CBLT-268:  echo XCODE_CMD to verify we are passing correct metadata

Change-Id: Ie9234f4dd9e7d692f027a958e81fd8764cda9e1b
Reviewed-on: http://review.couchbase.org/36895
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>