gulp-csso 
Minify CSS with CSSO.
If you have any difficulties with the output of this plugin, please use the CSSO tracker.
With npm do:
npm install gulp-csso --save-dev
var gulp = require('gulp');
var csso = require('gulp-csso');
gulp.task('default', function () {
return gulp.src('./main.css')
.pipe(csso())
.pipe(gulp.dest('./out'));
});A boolean value; the default is to use structure minimization for maximum compression, by passing false (or no parameters). See the CSSO description for more information. Pass true instead if you want to disable this feature.
Pull requests are welcome. If you add functionality, then please add unit tests to cover it.
MIT © Ben Briggs