Youtube API Login Required

Using nodejs, I try something as simple as what's below and get the output:

 { [Error: Login Required] code: 401 }
    null

The tutorials regarding the youtube api I've seen online all use youtube.discover('youtube','v3').execute() but that method no longer exists. What's wrong with my authentication? I just want to interact with youtube, server to server.

var gapi = require('googleapis');
var jwt = new gapi.auth.JWT(
    '___email___',
    './key.pem',
    null,
    [
        'http://ift.tt/1e5P8Hx'
    ],
    null
);
jwt.authorize(function(err,result) {
    var youtube = gapi.youtube({ version: 'v3', auth: result.access_token });
    var params = {
        id: 'JiPkDbjbN8w',
        rating: 'like'
    }
    youtube.videos.rate(params,function(err,result) {
        console.log(err);
        console.log(result);
    });
});