title: Dropdown in Angular6 with Bootstrap 4.1.3 does not work
body: <p>trying to implement a dropdown in an angular-app with bootstrap, I am having problems with the layout of the dropdown. The dropdown opens to the left of the button and not as a real dropdown to the bottom. Furthermore the complete navbar gets a new height. </p>
  
  <p><a href="https://i.stack.imgur.com/YIKBx.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/YIKBx.png" alt="enter image description here"></a></p>
  
  <p>My HTML looks like following:</p>
  
  <p><strong>HTML</strong></p>
  
  <pre><code>    &lt;div class="btn-group" &gt;
        &lt;button
          type="button class="
          btn btn-success dropdown-toggle"
          data-toggle="dropdown"
          aria-haspopup="false" 
          aria-expanded="false" 
          (click)="panelExpanded = !panelExpanded"&gt;Login
        &lt;/button&gt;
        &lt;div  *ngIf="panelExpanded" &gt;
          &lt;a class="dropdown-item" routerLink="/signin"&gt;Anmelden&lt;/a&gt;
          &lt;div class="dropdown-divider"&gt;&lt;/div&gt;
          &lt;a class="dropdown-item" routerLink="/signup"&gt;Registrieren&lt;/a&gt;
        &lt;/div&gt;
      &lt;/div&gt;
  </code></pre>
  
  <p><code>panelExpanded</code> is just a boolean in the .ts-file.</p>
  
  <p>I tried the two suggested solutions and both did not work so far:</p>
  
  <ol>
  <li>adding <code>class="dropdown-menu"</code></li>
  <li>installing bootstrap (see following)</li>
  </ol>
  
  <p>After adding following import-statement to the angular.json, it still does not work:</p>
  
  <p><code>"node_modules/bootstrap/dist/css/bootstrap.css",</code></p>
  
  <p>Additionally I installed ng-bootstrap</p>
  
  <p><code>npm install --save @ng-bootstrap/ng-bootstrap</code></p>
  
  <p>and bootstrap</p>
  
  <p><code>npm i --save bootstrap</code></p>
  
  <p>I got the following messages though:</p>
  
  <p><code>bootstrap@4.1.3 requires a peer of jquery@1.9.1</code></p>
  
  <p><code>bootstrap@4.1.3 requires a peer of popper.js@^1.14.3</code></p>
  
  <p>Do I have to install those two packages, as well?</p>
  
  <p>I tried to include the ng-bootstrap-script within angular.json, as well, still without success</p>
  
  <pre><code>"scripts": [
    "node_modules/@ng-bootstrap/ng-bootstrap/fesm5/ng-bootstrap.js",
  ]
  </code></pre>
  
  <p>Thanks in advance for any feedback.</p>