Livereload via Gulp and Jekyll build

gulpfile.js

var gulp = require('gulp');
var cp = require('child_process');
var shell  = require('gulp-shell');
var express = require('express');
var livereload = require('gulp-livereload');

gulp.task('default', ['watch']);

// Run static file server
gulp.task('serve', function () {
  var server = express();
  server.use(express.static('_site'));
  server.listen(4000);
});

// Watch for changed files
gulp.task('watch', ['jekyll', 'serve'], function () {
  // Create LiveReload server
  livereload.listen({ port: 35729, basePath: '_site' });
  // Watch files, reload on change
  gulp.watch('_site/**').on('change', function (file) {
    livereload.changed(file.path);
  });

  gulp.watch(['./*.html', '_layouts/*.haml', '_includes/*.haml', '**/*.md', '_sass/**/*.scss', './images/**/*', '!_site/**', '!_site/**/*'], ['jekyll']);
});

// Compile pages with Jekyll
gulp.task('jekyll', function () {
  return cp.spawn('jekyll', ['build']);
});