title: Return custom exit code in Spring Shell
body: <p>I am working on a spring-shell application, my @CliCommand methods have custom logic that ends with responses like SUCCESS / FAILURE.
  I saw that it is possible to modify the spring-shell exit code by throwing an exception (it becomes 1).</p>
  
  <p>In case of FAILURE I would like to return an exit code different from 0. Is it possible to do that without throwing an exception?</p>