title: Materialize dropdown doesn't work
body: <p>I'm trying to make a dropdown menu inside a sidebar with Materialize, but it doesn't work.
  the width of the dropdown isn't the same as the trigger and the padding move the anchor to the bottom of the list item. (The code is the same as the docs website)</p>
  
  <p>Here is a Codepen with the issue: <a href="http://codepen.io/anon/pen/QbNqgv">example</a></p>
  
  <p>Thanks for the help :)</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>$(document).ready(function(){
        
        // Sidebar
        $(".button-collapse").sideNav({menuWidth: 320, activationWidth: 70, edge: 'left'});
        // Dropdown
        $('.dropdown-button').dropdown({
             inDuration: 300,
             outDuration: 225,
             constrain_width: false, // Does not change width of dropdown to that of the activator
             hover: false, // Activate on hover
             gutter: 0, // Spacing from edge
             belowOrigin: false // Displays dropdown below the button
             }
        );
      });</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div id="slide-out" class="side-nav full"&gt;
    &lt;ul&gt;
        &lt;li&gt;&lt;a href="#"&gt;First Link&lt;/span&gt;&lt;/a&gt;&lt;/li&gt;
        &lt;li&gt;&lt;a href="#"&gt;Second Link&lt;/span&gt;&lt;/a&gt;&lt;/li&gt;
        &lt;!-- Dropdown Trigger --&gt;
        &lt;li&gt;&lt;a class='dropdown-button' href='#' data-activates='dropdown1'&gt;Drop Me!&lt;/a&gt;&lt;/li&gt;
    &lt;/ul&gt;
  &lt;/div&gt;
  
  &lt;ul id='dropdown1' class='dropdown-content'&gt;
      &lt;li&gt;&lt;a href="#!"&gt;one&lt;/a&gt;&lt;/li&gt;
      &lt;li&gt;&lt;a href="#!"&gt;two&lt;/a&gt;&lt;/li&gt;
      &lt;li class="divider"&gt;&lt;/li&gt;
      &lt;li&gt;&lt;a href="#!"&gt;three&lt;/a&gt;&lt;/li&gt;
  &lt;/ul&gt;
  
  &lt;div class="row"&gt;
    &lt;a href="#" data-activates="slide-out" class="button-collapse"&gt;&lt;i class="mdi-navigation-menu medium black-text left"&gt;&lt;/i&gt;&lt;/a&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>