title: How to use Subject in angular 6?
body: <p>I've been using Subject from <code>rxjs</code> library to make an event emitter in my angular applications but I'm not able to use it in Angular 6 as 
  This module isn't present there</p>
  
  <pre><code>Cannot find module 'rxjs/Subject'
  </code></pre>
  
  <p>Is being thrown.</p>
  
  <p>Is there a new way for what I've been doing like this.</p>
  
  <pre><code>import { Subject } from 'rxjs/Subject';
  private Login = new Subject&lt;boolean&gt;();
  </code></pre>
  
  <p>Then doing this <code>this.Login.next(true)</code></p>
  
  <p>I was able to change state in my project of the user:</p>
  
  <pre><code>loginService.Login.subscribe(state =&gt; {
        console.log('Login State')
        console.log(state)
  })
  </code></pre>
  
  <p><strong>How to do the above stuff in Angular 6</strong></p>