code: function saveManifest(manifest, request, host, fn) {
    request
      .post(host + '/manifest')
      .send({manifest: JSON.stringify(manifest)})
      .end(function(err, res) {
        if (err) return fn(err);
        if (res.error) return fn(res.error);
        fn(null, res.headers.location);
      });
  }
docs: Save the manifest file to the build server
  
  @param {Object} manifest
  @param {Request} request
  @param {String} host
  @param {Function} fn