The io.spring sample referred to in the openwhisk README isn't
in this repo, so users generally don't have it installed locally.
This change makes it more obvious that you have to create your
own.
Also fixes the `wsk ...` command lines (the order of arguments
was wrong - maybe the CLI changed?).
Lambdas generally only deal with single values anyway, but for
consistency we should return similar results from a Lambda handler
as from an MVC handler in s-c-f-web.
