code: function () {
        var pkgs = this.pkgs;
        var configNames = _.chain(pkgs)
          .map(function (pkg) { return _.keys(pkg.config); })
          .flatten()
          .uniq()
          .value();
  
        // Take "first" config value in arrays as "winning" value.
        return _.chain(configNames)
          .map(function (name) {
            return [name, _.find(pkgs, function (pkg) {
              return _.has(pkg.config, name);
            }).config[name]];
          })
          // Object.
          .reduce(function (memo, pair) {
            memo[pair[0]] = pair[1];
            return memo;
          }, {})
          .value();
      }
docs: Return object of resolved package.json config fields.
  
  Resolves in order of "root wins", then in reverse archetype order.
  
  @returns {Object} environment object.