templates: add missing single quotation marks

Author: Kátia Nakamura

pyconbalkan/core/templates/index.html

@@ -19,7 +19,7 @@
     <link rel="stylesheet" href="{% static 'css/style.css' %}">
 
     <!-- Timer JS -->
-    <script src="{% static js/timer.js %}" type="text/javascript"></script>
+    <script src="{% static 'js/timer.js' %}" type="text/javascript"></script>
 
     <!-- HTML5 shim and Respond.js for IE8 support of HTML5 elements and media queries -->
     <!--[if lt IE 9]>