Почему перестал работать мой gulpfile?

'use strict';

var gulp = require('gulp'),
    mainBowerFiles = require('main-bower-files'),
    watch = require('gulp-watch'),
    prefixer = require('gulp-autoprefixer'),
    uglify = require('gulp-uglify'),
    sourcemaps = require('gulp-sourcemaps'),
    sass = require('gulp-sass'),
    cleanCSS = require('gulp-clean-css'),
    imagemin = require('gulp-imagemin'),
    pngquant = require('imagemin-pngquant'),
    rimraf = require('rimraf'),
    browserSync = require("browser-sync"),
    reload = browserSync.reload;

var path = {
    vendor: {
        js: 'app/js/',
        css: 'app/css/'
    },
    dist: { 
        html: 'dist/',
        js: 'dist/js/',
        scss: 'dist/css/',
        css: 'dist/css/',
        img: 'dist/img/',
        fonts: 'dist/fonts/'
    },
    app: { 
        html: 'app/*.html',
        js: 'app/js/*.js', 
        scss: 'app/css/*.scss',
        css: 'app/css/*.css',
        img: 'app/img/**/*.*', 
        fonts: 'app/fonts/**/*.*'
    },
    watch: {
        html: 'app/**/*.html',
        js: 'app/js/**/*.js',
        scss: 'app/css/**/*.scss',
        css: 'app/css/**/*.css',
        img: 'app/img/**/*.*',
        fonts: 'app/fonts/**/*.*'
    },
    clean: './dist'
};

var config = {
    server: {
        baseDir: "./dist"
    },
};

gulp.task('vendorJs:build', function() {
    gulp.src(mainBowerFiles('**/*.js')) 
        .pipe(gulp.dest(path.vendor.js))
});

gulp.task('vendorCss:build', function() {
    gulp.src(mainBowerFiles('**/*.css')) 
        .pipe(gulp.dest(path.vendor.css)) 
});

gulp.task('html:build', function() {
    gulp.src(path.app.html)
        .pipe(gulp.dest(path.dist.html)) 
        .pipe(reload({ stream: true })); 
});

gulp.task('js:build', function() {
    gulp.src(path.app.js)
        .pipe(sourcemaps.init())
        .pipe(uglify()) 
        .pipe(sourcemaps.write()) 
        .pipe(gulp.dest(path.dist.js))
        .pipe(reload({ stream: true })); 
});

gulp.task('scss:build', function() {
    gulp.src(path.app.scss) 
        .pipe(sourcemaps.init()) 
        .pipe(sass())
        .pipe(prefixer()) 
        .pipe(cleanCSS()) 
        .pipe(sourcemaps.write())
        .pipe(gulp.dest(path.dist.scss))
        .pipe(reload({ stream: true }));
});

gulp.task('css:build', function() {
    gulp.src(path.app.css) 
        .pipe(sourcemaps.init())
        .pipe(gulp.dest(path.dist.css)) 
        .pipe(reload({ stream: true }));
});

gulp.task('image:build', function() {
    gulp.src(path.app.img) 
        .pipe(imagemin({ 
            progressive: true,
            svgoPlugins: [{ removeViewBox: false }],
            use: [pngquant()],
            interlaced: true
        }))
        .pipe(gulp.dest(path.dist.img)) 
        .pipe(reload({ stream: true }));
});

gulp.task('fonts:build', function() {
    gulp.src(path.app.fonts)
        .pipe(gulp.dest(path.dist.fonts))
});

gulp.task('build', [
    'vendorCss:build',
    'vendorJs:build',
    'html:build',
    'js:build',
    'scss:build',
    'css:build',
    'fonts:build',
    'image:build'
]);

gulp.task('watch', function() {
    watch([path.watch.html], function(event, cb) {
        gulp.start('html:build');
    });
    watch([path.watch.scss], function(event, cb) {
        gulp.start('scss:build');
    });
    watch([path.watch.css], function(event, cb) {
        gulp.start('css:build');
    });
    watch([path.watch.js], function(event, cb) {
        gulp.start('js:build');
    });
    watch([path.watch.img], function(event, cb) {
        gulp.start('image:build');
    });
    watch([path.watch.fonts], function(event, cb) {
        gulp.start('fonts:build');
    });
});

gulp.task('webserver', function() {
    browserSync(config);
});

gulp.task('clean', function(cb) {
    rimraf(path.clean, cb);
});

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

{
  "name": "testgulp",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "dependencies": {
    "browser-sync": "^2.2.3",
    "gulp": "latest",
    "gulp-autoprefixer": "^2.1.0",
    "gulp-clean-css": "latest",
    "gulp-imagemin": "^2.2.1",
    "gulp-sass": "latest",
    "gulp-sourcemaps": "^1.5.0",
    "gulp-uglify": "^1.1.0",
    "gulp-watch": "^4.1.1",
    "imagemin-pngquant": "^4.0.0",
    "main-bower-files": "^2.13.1",
    "rimraf": "^2.3.1"
  },
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC"
}

"overrides":
    {
        "bootstrap":
        {
            "main": [
                "./dist/js/bootstrap.min.js",
                "./dist/css/bootstrap.min.css"
            ]
        },
        "jquery":
        {
            "main": "dist/jquery.min.js"
        }
    }