docs: function validateSeed() {
    return Q.Promise(function(resolve, reject) {
      https.get('https://github.com/olivejs/seed-' + options.seed, function(res) {
        if (res.statusCode === 200) {
          resolve('>> seed exists');
        } else {
          reject(new Error('Invalid seed: ' + options.seed));
        }
      }).on('error', function(err) {
        logger.error('\n  %s\n', err.message);
        reject(err);
      });
    });
  }