Adding new job with socket.io socket in data results with fail

Adding new job with socket.io socket in data results with fail with empty error object.

NOT-WORKING:

```
io.on('connection',function(socket){
queue
.create('getPostData',{socket:socket,data:data})
.attempts(3)
.priority('critical')
.save(function(err){
if(err){
return io.emit('getPostData',{result:false, message:'Cannot add task to queue',err:err});
}
});
}
```

WORKING:

```
io.on('connection',function(socket){
queue
.create('getPostData',{socketId:socket.id,data:data})
.attempts(3)
.priority('critical')
.save(function(err){
if(err){
return io.emit('getPostData',{result:false, message:'Cannot add task to queue',err:err});
}
});
}
```

And then restoring socket object by it's id.

The issue provides only connection-handler reproduction snippets, with no source file or test named. Start by tracing queue.create and how job data is serialized, then compare passing the socket object with passing socket.id; done means the reported failure is handled or clearly rejected and covered by a regression test.

Written by the indexing model from the issue text.