docs: function concatBanner() {
  	if (typeof argv.banner !== 'undefined') {
  		if (argv.banner) {
  			return Promise.resolve().then(() => {
  				concat.add(null, require(path.join(process.cwd(), argv.banner)));
  				return log('banner', argv.banner);
  			});
  		}
  		return readPkg().then(pkg => {
  			concat.add(null, getDefaultBanner(pkg.pkg));
  			return log('dbanner', pkg.path);
  		});
  	}
  	return Promise.resolve();
  }