migrating - Note that DedupePlugin has been removed

Author: bebraw

content/guides/migrating.md

@@ -10,6 +10,7 @@ contributors:
   - jouni-kantola
   - frederikprijck
   - chrisVillanueva
+  - bebraw
 ---
 
 ## `resolve.root`, `resolve.fallback`, `resolve.modulesDirectories`
@@ -226,6 +227,10 @@ To keep compatibility with old loaders, loaders can be switched to minimize mode
   ]
 ```
 
+## `DedupePlugin` has been removed
+
+`webpack.optimize.DedupePlugin` isn't needed anymore. Remove it from your configuration.
+
 ## `BannerPlugin` - breaking change
 
 `BannerPlugin` no longer accept two parameters but rather only a single options object.