Update gulp 4.0

[miguelcalderons]

var gulp        = require('gulp');
var sass        = require('gulp-sass');
var browserSync = require('browser-sync');
var reload      = browserSync.reload;

function style() {
  return gulp
    .src(paths.styles.src)
    .pipe(sass())
    .on("error", sass.logError)
    .pipe(gulp.dest(paths.styles.dest))
    .pipe(reload({stream:true}));
}

exports.style = style;


function watch() {
  browserSync.init({
    proxy: 'localhost/umai/dcg',
    notify: false
  });
  gulp.watch(paths.styles.dest, style);
}

exports.watch = watch


var paths = {
  styles: {
    src: "sass/**/*.scss",
    dest: "styles"
  }
};