onCompleted on job.finished should capture result from queue process

Created by: saviogrossi

The result of a .process(), when exists, is always passed on 'completed' event, so it's make sense to capture that value on onCompleted handler.

Now this should works:

service1Queue.add({hello: 'world'}).then(function(job) {
    return job.finished();
}).then(function(result) {
   // do something with result...
}).catch(function(err) {
   // catch err
})