update webpack-dev-server to include fix for DynamicEntryPlugin support

package.json

@@ -118,6 +118,6 @@
     "karma-webpack": "2.0.7",
     "nodemon": "^1.15.1",
     "prettier": "1.9.2",
-    "webpack-dev-server": "^2.11.1"
+    "webpack-dev-server": "^2.11.2"
   }
 }

yarn.lock

@@ -8745,9 +8745,9 @@ webpack-dev-middleware@1.12.2, webpack-dev-middleware@^1.12.0:
     range-parser "^1.0.3"
     time-stamp "^2.0.0"
 
-webpack-dev-server@^2.11.1:
-  version "2.11.1"
-  resolved "https://registry.yarnpkg.com/webpack-dev-server/-/webpack-dev-server-2.11.1.tgz#6f9358a002db8403f016e336816f4485384e5ec0"
+webpack-dev-server@^2.11.2:
+  version "2.11.2"
+  resolved "https://registry.yarnpkg.com/webpack-dev-server/-/webpack-dev-server-2.11.2.tgz#1f4f4c78bf1895378f376815910812daf79a216f"
   dependencies:
     ansi-html "0.0.7"
     array-includes "^3.0.3"