code: function() {
    return Promise.resolve()
    .then(function() { return npm.loadAsync(); })
    .then(function(npm) {
      npm.config.set('spin', false);
      npm.config.set('global', true);
      npm.config.set('depth', 0);
      return Promise.promisify(npm.commands.list)([], true);
    })
    .then(function(data) { return data; });
  }
docs: Get a list of all global npm modules.
  
  @private
  @function setup.plugins.~modules
  @return {Promise}