у я не могу переключить навигационную панель при изменении размера на мобильный экран в angular 4 с помощью начальной загрузки 4. Я включил его в angular cli в скрипте и стилях, модулях узла из начальной загрузки. Чего-то не хватает в моем коде? Пожалуйста, проверьте ниже. Что-то не так? Пожалуйста помоги

<nav class="navbar navbar-expand-md navbar-dark fixed-top bg-dark">
  <a class="navbar-brand" href="#">Dashboard</a>
  <button class="navbar-toggler d-lg-none" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>

  <div class="collapse navbar-collapse" id="navbarsExampleDefault">
    <ul class="navbar-nav mr-auto">
      <li class="nav-item active">
        <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#">Settings</a>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#">Profile</a>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#">Help</a>
      </li>
    </ul>
    <form class="form-inline mt-2 mt-md-0">
      <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
      <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
    </form>
  </div>
</nav>

.angular-cli.json

 "styles": [
    "styles.css",
     "../node_modules/bootstrap/dist/css/bootstrap.min.css"
  ],
  "scripts": [

    "../node_modules/popper.js/dist/umd/popper.min.js",
    "../node_modules/jquery/dist/jquery.min.js",
    "../node_modules/bootstrap/dist/js/bootstrap.min.js"

  ],

package.json

      {
  "name": "dashboard2",
  "version": "0.0.0",
  "license": "MIT",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "^4.0.0",
    "@angular/common": "^4.0.0",
    "@angular/compiler": "^4.0.0",
    "@angular/core": "^4.0.0",
    "@angular/forms": "^4.0.0",
    "@angular/http": "^4.0.0",
    "@angular/platform-browser": "^4.0.0",
    "@angular/platform-browser-dynamic": "^4.0.0",
    "@angular/router": "^4.0.0",
    "bootstrap": "^4.0.0-beta",
    "core-js": "^2.4.1",
    "jquery": "^3.2.1",
    "popper.js": "^1.12.5",
    "rxjs": "^5.4.1",
    "zone.js": "^0.8.14"
  },
  "devDependencies": {
    "@angular/cli": "1.2.7",
    "@angular/compiler-cli": "^4.0.0",
    "@angular/language-service": "^4.0.0",
    "@types/jasmine": "~2.5.53",
    "@types/jasminewd2": "~2.0.2",
    "@types/node": "~6.0.60",
    "codelyzer": "~3.0.1",
    "jasmine-core": "~2.6.2",
    "jasmine-spec-reporter": "~4.1.0",
    "karma": "~1.7.0",
    "karma-chrome-launcher": "~2.1.1",
    "karma-cli": "~1.0.1",
    "karma-coverage-istanbul-reporter": "^1.2.1",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "protractor": "~5.1.2",
    "ts-node": "~3.0.4",
    "tslint": "~5.3.2",
    "typescript": "~2.3.3"
  }
}