Bump main.css and main.js version numbers to bust caches

Author: Bjwebb

prefix_finder/frontend/templates/base.html

@@ -18,7 +18,7 @@
     <!-- Styles -->
     <link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
     <link rel="stylesheet" href="{% static 'css/chosen.min.css'%}?version=2">
-    <link rel="stylesheet" href="{% static 'css/main.css'%}?version=3">
+    <link rel="stylesheet" href="{% static 'css/main.css'%}?version=4">
     {% get_favicons prefix="favicons/" %}
   </head>
 
@@ -38,7 +38,7 @@
     <script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script>
     <script src="{% static 'js/progress-bar.js'%}"></script>
     <script src="{% static 'js/chosen.min.js'%}"></script>
-    <script src="{% static 'js/main.js'%}?version=2"></script>
+    <script src="{% static 'js/main.js'%}?version=3"></script>
 
     {% if piwik.url and piwik.site_id %}
       <!-- Piwik -->