Register a function into redis.

[pedrosnk]

By doing a POST to the url

/functions/:namespace/:function_name

passing withing the body:

{
  "code": "
    function main(req, res) {
      res.send(\"Hello World\");
    }
  "
}

The function must be registered inside the Functions to be executed later on

[wpjunior]

Right now, it's possible to PUT the function into backstage functions.