public function showRevisions($bookSlug, $pageSlug)
{
$book = $this->bookRepo->getBySlug($bookSlug);
$page = $this->pageRepo->getBySlug($pageSlug, $book->id);
$this->setPageTitle('Revisions For ' . $page->getShortName());
return view('pages/revisions', ['page' => $page, 'book' => $book, 'current' => $page]);
}