MB-12594: Add goxdcr

Change-Id: Ia4fe5bdb7340d642a0b3a28406c4ef79eb04a8b3
Reviewed-on: http://review.couchbase.org/43001
Reviewed-by: Chris Hillery <ceej@couchbase.com>
Tested-by: Chris Hillery <ceej@couchbase.com>