Gulp Uncss multiple files

gistfile1.js

npm install glob --save-dev
npm install gulp-uncss --save-dev

var uncss = require('gulp-uncss');
var glob = require('glob');

gulp.task('uncss', function() {
  gulp.src('public/css/dirty.css')
    .pipe(uncss({
      html: glob.sync('app/views/**/*.*')
    }))
    .pipe(gulp.dest('public/css/clean.css'));
});