gutil.env.production
var prod = gutil.env.production;
var dist = prod ? 'production/' : 'dist/';
gulp.task('js-libs', function() {
return gulp.src(app + 'src/libs.js')
.pipe(prod ? uglify() : gutil.noop())
.pipe(gulp.dest(dist + 'js'))
.pipe(reload({stream: true}));
});