title: File is not being downloaded on Laravel5 using Response
body: <p>I use Laravel 5.1.</p>
  
  <p>A jQuery ajax call is made like that:</p>
  
  <pre><code>$('#export_selected').click(function(){
                  var checked = $('.select_rows:checked');
                  var ids     = [];
                  $.each(checked, function(index, value){
                      ids.push(value.id);
                  })
                  $.ajax({
                      method : "POST",
                      url    : "{{URL::to('/spot/exportTable')}}",
                      data   : {ids:ids}
                  });
              });
  </code></pre>
  
  <p>And then the php method is defined that way:</p>
  
  <pre><code>public function exportTable(Request $req) {
              $spots = array_flatten($req-&gt;all());
              $res   = Spot::whereIn('id', $spots)-&gt;get();
  
              Excel::create('Spots', function($excel) use($res) {
                  $excel-&gt;setTitle('Title goes here');
                  $excel-&gt;setCreator('Creator Goes Here')-&gt;setCompany('Company Goes Here');
                  $excel-&gt;sheet('Excel sheet', function($sheet) use($res) {
                      $sheet-&gt;setOrientation('landscape');
                      $sheet-&gt;fromArray($res);
                  });
              })-&gt;store('csv', storage_path('/exports', true));
  
              $file    = base_path() . '/storage/exports/Spots.csv';
              $headers = ['Content-Type: application/csv',  'Content Description: File Transfer', 'Cache-Control: must-revalidate, post-check=0, pre-check=0'];
              return response()-&gt;download($file, 'Spots.csv' , $headers);
      }
  </code></pre>
  
  <p>Chrome developer console prints the results as raw lines.</p>
  
  <p>The file is successfully exported and created in the disk.</p>
  
  <p>The path to file is correct.</p>
  
  <p>But the download is never started.</p>
  
  <p>Echoing the response gives:</p>
  
  <pre><code>HTTP/1.0 200 OK
  0:                   Content-Type: application/csv
  Cache-Control:       public
  Content-Disposition: attachment; filename="Spots.csv"
  Date:                Mon, 26 Oct 2015 16:08:26 GMT
  Last-Modified:       Mon, 26 Oct 2015 16:08:26 GMT
  1:                   Content-Description: File Transfer
  2:                   Cache-Control: must-revalidate, post-check=0, pre-check=0
  </code></pre>