Only configure the dev server in the dev environment

Then Webpacker.dev_server.running? will return false in testing even though the dev server is running, so on-demand testing will work as expected.

Author: David Heinemeier Hansson

lib/install/config/webpacker.yml

@@ -10,11 +10,6 @@ default: &default
   # ['app/assets', 'engine/foo/app/assets']
   resolved_paths: []
 
-  # webpack-dev-server configuration
-  dev_server: &dev_server
-    host: localhost
-    port: 3035
-
   extensions:
     - .coffee
     - .erb
@@ -35,6 +30,10 @@ development:
   <<: *default
   compile: true
 
+  dev_server:
+    host: localhost
+    port: 3035
+
 test:
   <<: *default
   compile: true