title: CSS minify and rename with gulp
body: <p>I've a variable like</p>
  
  <pre><code>var files = {
      'foo.css': 'foo.min.css',
      'bar.css': 'bar.min.css',
  };
  </code></pre>
  
  <p>What I want the gulp to do for me is to <code>minify</code> the files and then <code>rename</code> for me.</p>
  
  <p>But the tasks is currently written as (for one file)</p>
  
  <pre><code>gulp.task('minify', function () {
      gulp.src('foo.css')
          .pipe(minify({keepBreaks: true}))
          .pipe(concat('foo.min.css'))
          .pipe(gulp.dest('./'))
  });
  </code></pre>
  
  <p>How to rewrite so it work with my variable <code>files</code> defined above?</p>