Bump release notes date (#3626)

Author: brandonferrua

RELEASENOTES.md

@@ -1,7 +1,7 @@
 <!-- Release notes authoring guidelines: http://keepachangelog.com/ -->
 <!-- !!! THIS FILE IS AUTO-GENERATED !!! DO NOT EDIT THIS FILE MANUALLY !!! -->
 
-## Release 2.8.0 - December 20, 2018
+## Release 2.8.0 - January 4, 2019
 
 ## Components
 
@@ -225,6 +225,13 @@
 
 
 
+### [Setup Assistant](https://www.lightningdesignsystem.com/components/setup-assistant)
+
+#### Added
+- Added `slds-container_fluid` to the div containing a step's title and content in order to display the Setup Assistant properly in IE11
+
+
+
 ### [Split View](https://www.lightningdesignsystem.com/components/split-view)
 
 #### Changed