Prevent caching of CSS in development mode

Change-Id: Ifdabe22a729ba72eb311bc5daa5cc5b22a20f0f2
diff --git a/templates/layouts/main.html.ep b/templates/layouts/main.html.ep
index e23c589..fcc8bbe 100644
--- a/templates/layouts/main.html.ep
+++ b/templates/layouts/main.html.ep
@@ -41,7 +41,6 @@
 
     <link rel="apple-touch-icon" href="<%= url_for '/img/apple-touch-icon.png' %>" />
     <link href="<%= stash 'prefix' %>/favicon.ico" rel="shortcut icon" type="image/x-icon" /> 
-    <link href="<%= stash 'prefix' %>/css/kalamar-<%= $Kalamar::VERSION %>.css" type="text/css" rel="stylesheet" />
     
 %= javascript begin  
   window.KorAP = window.KorAP || {};
@@ -51,8 +50,10 @@
 % end
 
 % if ($c->app->mode eq 'development') {
+    <link href="<%= stash 'prefix' %>/css/kalamar-<%= $Kalamar::VERSION %>.css?v=<%= random_string %>" type="text/css" rel="stylesheet" />
     <script data-main="/js/src/app/devel" src="/js/lib/require.js" async="async"></script>
 % } else {
+    <link href="<%= stash 'prefix' %>/css/kalamar-<%= $Kalamar::VERSION %>.css" type="text/css" rel="stylesheet" />
     <script src="<%= (stash('prefix') // '') . '/js/' . loc('jsFile', 'kalamar-' . $Kalamar::VERSION . '-en.js') %>" async="async"></script>
 % };