public function deleteDocument(Request $request, Document $document)
 {
     // Does this document belong to the current user?
     if ($document->user->id != Auth::user()->id) {
         $request->session()->flash('error', 'Only the person who uploaded a file may delete it.');
         return redirect('/login');
     }
     $path = public_path() . '/files/user/' . $document->file;
     $document->delete();
     File::delete($path);
     $request->session()->flash('success', 'Your file has been deleted.');
     return redirect()->back();
 }