First shot at happy-path observe.

Change-Id: Id81a062531bd9a10fb1dc7c9c878a4ee7b90cd2f
Reviewed-on: http://review.couchbase.org/39485
Reviewed-by: Michael Nitschinger <michael.nitschinger@couchbase.com>
Tested-by: Michael Nitschinger <michael.nitschinger@couchbase.com>