title: Using filter(chunk) gives error
body: <p>I am using Laravel-Excel 2.1. I am trying to use chunk() to read a large imported Excel file but I got the error "Method noHeading does not exist."</p>
  
  <p><strong>My original code</strong></p>
  
  <p>This code works fine reading the imported files.</p>
  
  <pre><code>$column_number = 5;
  $rows = Excel::load('storage/app/public/upload/myfiles.xlsx', function($reader) use ($column_number)
  {
      $reader-&gt;noHeading();
      $reader-&gt;takeColumns($column_number);
      $reader-&gt;setDateFormat('d-m-Y');
  
  })-&gt;get();
  </code></pre>
  
  <p><strong>After using chunks as in documentation</strong></p>
  
  <p>This code gives <code>Method noHeading does not exist.</code> error. Notice I added <code>filter('chunk')</code> and <code>chunk(250</code></p>
  
  <pre><code>$column_number = 5;
  $rows = Excel::filter('chunk')-&gt;load('storage/app/public/upload/myfiles.xlsx')-&gt;chunk(250, function($reader) use ($column_number)
  {
      $reader-&gt;noHeading();
      $reader-&gt;takeColumns($column_number);
      $reader-&gt;setDateFormat('d-m-Y');
  
  })-&gt;get();
  </code></pre>