chore(rebuild): move redirect generation to prod to improve performance

Including this plugin in `common` causes it to be run twice for production builds as both
parallelized configs pick this up. We only need it in `prod` and it's kind of nice to have
all html generation happen in one build so lumping it together with the `SSGPlugin` makes
sense.

Author: skipjack

webpack.common.js

@@ -6,7 +6,6 @@ const CleanPlugin = require('clean-webpack-plugin');
 const CopyWebpackPlugin = require('copy-webpack-plugin');
 const ExtractTextPlugin = require('extract-text-webpack-plugin');
 const DirectoryTreePlugin = require('directory-tree-webpack-plugin');
-const RedirectWebpackPlugin = require('redirect-webpack-plugin');
 
 module.exports = (env = {}) => ({
   devtool: 'source-map',
@@ -128,39 +127,6 @@ module.exports = (env = {}) => ({
           // TODO: Add directory (section) attributes and index url (if necessary)
         }
       }
-    }),
-    new RedirectWebpackPlugin({
-      redirects: {
-        'support': '/contribute/',
-        'writers-guide': '/contribute/writers-guide/',
-        'get-started': '/guides/getting-started/',
-        'get-started/install-webpack': '/guides/installation/',
-        'get-started/why-webpack': '/guides/why-webpack/',
-        'pluginsapi': '/api/plugins/',
-        'pluginsapi/compiler': '/api/compiler-hooks/',
-        'pluginsapi/template': '/api/template/',
-        'api/passing-a-config': '/configuration/configuration-types/',
-        'api/plugins/compiler': '/api/compiler-hooks/',
-        'api/plugins/compilation': '/api/compilation/',
-        'api/plugins/module-factories': '/api/module-methods/',
-        'api/plugins/parser': '/api/parser/',
-        'api/plugins/tapable': '/api/tapable/',
-        'api/plugins/template': '/api/template/',
-        'api/plugins/resolver': '/api/resolver/',
-        'development': '/contribute/',
-        'development/plugin-patterns': '/contribute/plugin-patterns/',
-        'development/release-process': '/contribute/release-process/',
-        'development/how-to-write-a-loader': '/contribute/writing-a-loader/',
-        'development/how-to-write-a-plugin': '/contribute/writing-a-plugin/',
-        'guides/code-splitting-import': '/guides/code-splitting/',
-        'guides/code-splitting-require': '/guides/code-splitting/',
-        'guides/code-splitting-async': '/guides/code-splitting/',
-        'guides/code-splitting-css': '/guides/code-splitting/',
-        'guides/code-splitting-libraries': '/guides/code-splitting/',
-        'guides/why-webpack': '/comparison/',
-        'guides/production-build': '/guides/production/',
-        'migrating': '/migrate/3/'
-      },
     })
   ],
   stats: {

webpack.prod.js

@@ -4,6 +4,7 @@ const webpack = require('webpack');
 const merge = require('webpack-merge');
 const UglifyJSPlugin = require('uglifyjs-webpack-plugin');
 const SSGPlugin = require('static-site-generator-webpack-plugin');
+const RedirectWebpackPlugin = require('redirect-webpack-plugin');
 
 // Load Common Configuration
 const common = require('./webpack.common.js');
@@ -31,6 +32,39 @@ module.exports = env => [
         globals: {
           window: {}
         }
+      }),
+      new RedirectWebpackPlugin({
+        redirects: {
+          'support': '/contribute/',
+          'writers-guide': '/contribute/writers-guide/',
+          'get-started': '/guides/getting-started/',
+          'get-started/install-webpack': '/guides/installation/',
+          'get-started/why-webpack': '/guides/why-webpack/',
+          'pluginsapi': '/api/plugins/',
+          'pluginsapi/compiler': '/api/compiler-hooks/',
+          'pluginsapi/template': '/api/template/',
+          'api/passing-a-config': '/configuration/configuration-types/',
+          'api/plugins/compiler': '/api/compiler-hooks/',
+          'api/plugins/compilation': '/api/compilation/',
+          'api/plugins/module-factories': '/api/module-methods/',
+          'api/plugins/parser': '/api/parser/',
+          'api/plugins/tapable': '/api/tapable/',
+          'api/plugins/template': '/api/template/',
+          'api/plugins/resolver': '/api/resolver/',
+          'development': '/contribute/',
+          'development/plugin-patterns': '/contribute/plugin-patterns/',
+          'development/release-process': '/contribute/release-process/',
+          'development/how-to-write-a-loader': '/contribute/writing-a-loader/',
+          'development/how-to-write-a-plugin': '/contribute/writing-a-plugin/',
+          'guides/code-splitting-import': '/guides/code-splitting/',
+          'guides/code-splitting-require': '/guides/code-splitting/',
+          'guides/code-splitting-async': '/guides/code-splitting/',
+          'guides/code-splitting-css': '/guides/code-splitting/',
+          'guides/code-splitting-libraries': '/guides/code-splitting/',
+          'guides/why-webpack': '/comparison/',
+          'guides/production-build': '/guides/production/',
+          'migrating': '/migrate/3/'
+        }
       })
     ],
     output: {