don't ship cli ebucketmigrator anymore

It's barely useful and tap's days are counted

Change-Id: Ib7f673c18406951a5db5875c926ff710fc08e0e2
Reviewed-on: http://review.couchbase.org/33150
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>