Input/Output Options Support

[jzachary]

Asana has some input/output options available in the API: https://developers.asana.com/docs/input-output-options

Would be great to be able to send Opt_fields in the asana() function:

asana()->getTasksWithTag($tags[$key]->gid, $opt_fields);

Here's a working example of it just hacked into a function:

public function getTasksWithTag($tagId)
    {
        return $this->curl->get("tags/{$tagId}/tasks?opt_fields=name,assignee.name,due_on,permalink_url,tags.name,this.custom_fields");
    }