Add optional block for more scripts in template

rd_ui/app/signed_out_layout.html

@@ -40,6 +40,8 @@
 <!-- build:js /scripts/layout_vendor.js -->
 <script src="/bower_components/jquery/jquery.js"></script>
 <!-- endbuild -->
+{% block scripts %}
+{% endblock %}
 
 {% include '_includes/signed_out_tail.html' %}