Remove webpack-dev-server upgrade (#1356)

In the Upgrade section the readme had `yarn upgrade webpack-dev-server --latest`. This will cause issues related to #1295 until webpacker supports webpack 4.0.
rails · Mar 15, 2018 · 93386ed · 93386ed
1 parent 811796a
commit 93386ed
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/README.md b/README.md
@@ -202,7 +202,7 @@ You can run following commands to upgrade Webpacker to the latest stable version
 ```bash
 bundle update webpacker
 yarn upgrade @rails/webpacker --latest
-yarn upgrade webpack-dev-server --latest
+yarn add webpack-dev-server@^2.11.1
 ```
 
 ### Yarn Integrity