Теперь так выглядит мой gulpfile
var gulp = require('gulp'),
watch = require('gulp-watch'),
prefixer = require('gulp-autoprefixer'),
uglify = require('gulp-uglify'),
sass = require('gulp-sass'),
csscomb = require('gulp-csscomb'),
uncss = require('gulp-uncss'),
concat = require('gulp-concat'),
cssmin = require('gulp-minify-css'),
imagemin = require('gulp-imagemin'),
pngquant = require('imagemin-pngquant'),
rimraf = require('rimraf'),
browserSync = require("browser-sync"),
reload = browserSync.reload;