Update to latest Bootstrap 3 (RC2)

lib/config.php

@@ -21,7 +21,7 @@ define('POST_EXCERPT_LENGTH', 40);
 function roots_main_class() {
   if (roots_display_sidebar()) {
     // Classes on pages with the sidebar
-    $class = 'col-sm-8 col-lg-8';
+    $class = 'col-sm-8 col-md-8 col-lg-8';
   } else {
     // Classes on full width pages
     $class = 'col-lg-12';
@@ -34,7 +34,7 @@ function roots_main_class() {
  * .sidebar classes
  */
 function roots_sidebar_class() {
-  return 'col-sm-4 col-lg-4';
+  return 'col-sm-4 col-md-4 col-lg-4';
 }
 
 /**