MB-100: point to master for 2.5 release

Change-Id: Ibed3c243b0a0ecf9717d9592ea37f3150c14999f
Reviewed-on: http://review.couchbase.org/29722
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>