Usemin-help

estou tentando fazer o usemin funcionar, não consigo achar o erro, ele simplesmente não faz o replace da tag script, não concatena e minifica mais ambos: css,js, quando eu estava usando os modulos separados estava funcionando, alguem poderia me ajudar? e nao da erro algum quando executo o npm run gulp:

const gulp = require('gulp'),
    imagemin = require('gulp-imagemin'),
    clean = require('gulp-clean'),
    concat = require('gulp-concat'),
    htmlReplace = require('gulp-html-replace'),
    uglify = require('gulp-uglify'),
    usemin = require('gulp-usemin'),
    cssmin = require('gulp-cssmin');

gulp.task('default', ['copy'], function () {
    gulp.start('build-img', 'usemin')
});

gulp.task('copy', ['clean'], function () {

    gulp.src('site/**/*')
        .pipe(gulp.dest('dist'));
});

gulp.task('clean', function () {
    return gulp.src('dist')
        .pipe(clean());
});

gulp.task('build-img', function () {

    return gulp.src('site/images/**/*')
        .pipe(imagemin())
        .pipe(gulp.dest('dist/images'));
});

gulp.task('usemin', function () {
    gulp.src('dist/**/*.php')
    .pipe(usemin({
        'js' : [uglify],
        'css' : [cssmin]
    }))
    .pipe(gulp.dest('dist'));
});


termina:[14:25:52] Using gulpfile ~\tempo\Desktop\sites\allPort\gulpfile.js
[14:25:52] Starting 'clean'...
[14:25:53] Finished 'clean' after 402 ms
[14:25:53] Starting 'copy'...
[14:25:53] Finished 'copy' after 3.4 ms
[14:25:53] Starting 'default'...
[14:25:53] Starting 'build-img'...
[14:25:53] Starting 'usemin'...
[14:25:53] Finished 'usemin' after 76 ms
[14:25:53] Finished 'default' after 90 ms
[14:25:59] gulp-imagemin: Minified 259 images (saved 650.82 kB - 5.5%)
[14:25:59] Finished 'build-img' after 6.65 s

packet.json:
{
  "name": "allPort",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "gulp": "gulp"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "gulp": "^3.9.0",
    "gulp-clean": "^0.3.1",
    "gulp-concat": "^2.6.0",
    "gulp-cssmin": "^0.2.0",
    "gulp-html-replace": "^1.5.4",
    "gulp-imagemin": "^2.3.0",
    "gulp-uglify": "^1.4.1",
    "gulp-usemin": "^0.3.14"
  }
}