Update release notes

RELEASE-NOTES.md

@@ -3,7 +3,7 @@
 ### Version 1.2.1 - December 09, 2014
 
 **Bugs**
-
+- *All UI** - Adds error message when triggering an invalid module behavior i.e. typos ``$('.dropdown').dropdown('hid');``
 - **Step** - Fix issue with completed ordered step icon alignment
 - **Sidebar** - Mobile sidebars now only set ``overflow`` on page's ``html`` when browsing from ``iOS` devices. Using overflow caused issues with page's scroll being lost when resizing a browser to mobile widths. This also affected modules that used  `$(window).scrollTop()`` at mobile screen sizes