title: Ionic sticky element inside scrollable content
body: <p>I am trying to make a sticky element in ionic but not sure how to achieve this.
  I have a back arrow that I would like to have in a fixed position. This is my html:</p>
  
  <pre><code>&lt;ion-content&gt;
      &lt;div class="back-arrow"&gt;
        &lt;a class="button button-icon icon ion-chevron-left" ui-sref="main.front"&gt;
        &lt;/a&gt;
      &lt;/div&gt;
  
  ...rest of the code...
  
  &lt;/ion-content&gt;
  </code></pre>
  
  <p>And this is my css:</p>
  
  <pre><code>.back-arrow {
    width: 100%;
    height: 48px;
    position: absolute;
    top:0;
    z-index: 1;
  }
  </code></pre>
  
  <p>To make it clearer. When I have:</p>
  
  <pre><code>&lt;div class="back-arrow"&gt;
            &lt;a class="button button-icon icon ion-chevron-left" ui-sref="main.front"&gt;
            &lt;/a&gt;
          &lt;/div&gt;
  &lt;ion-content&gt;
    ...rest of the code...   
  &lt;/ion-content&gt;
  </code></pre>
  
  <p>Then it is working, but when it is inside ion-content it is not sticky, and I need it inside of content.</p>