[CHANGELOG] Add entry for #233

Author: mrackwitz

CHANGELOG.md

@@ -2,6 +2,12 @@
 
 ## Master
 
+##### Enhancements
+
+* The linter fails now if root attributes occur on subspec level.
+  [Marius Rackwitz](https://github.com/mrackwitz)
+  [#233](https://github.com/CocoaPods/Core/pull/233)
+
 ##### Bug Fixes
 
 * Inhibit warnings for pods that only have the `inhibit_warnings` option enabled