title: Angular / ngx-translate Using separate translation in inner module does not work
body: <p><strong>What we want to do</strong></p>
  
  <p>Use a separate translateLoader that loads it's own translations for a certain module in our app.</p>
  
  <p><strong>What we have tried</strong></p>
  
  <p>Al lot of different combinations of <code>TranslateModule.forChild</code>/<code>TranslateModule.forRoot</code>, with or without <code>isolate: true</code></p>
  
  <p><strong>Plunker to show the issue</strong></p>
  
  <p><a href="https://embed.plnkr.co/iw7fnwRwK0BbySVKxnZd/" rel="noreferrer">https://embed.plnkr.co/iw7fnwRwK0BbySVKxnZd/</a></p>
  
  <p>Are we doing something wrong or is this an issue in ngx-translate?</p>
  
  <p>p.s. I have posted the same issue in the GitHub issues of ngx-translate: <a href="https://github.com/ngx-translate/core/issues/682" rel="noreferrer">https://github.com/ngx-translate/core/issues/682</a></p>