Add mchello to test the hello command

Change-Id: I91873f793b6d4d99ea200861796c256e5dca5bfd
Reviewed-on: http://review.couchbase.org/33245
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>