Add babel-preset-es2015 to babel-register and webpack

- Save dependency:
  * babel-preset-es2015@6.24.0
- Ensure ES6 is compiled to ES5:
  - On server (add preset to `babel-register`)
  - On client (add preset to babel-loader in `webpack.config.js`)

Author: remarkablemark

package.json

@@ -19,6 +19,7 @@
   "dependencies": {
     "babel-core": "^6.9.0",
     "babel-loader": "^6.2.4",
+    "babel-preset-es2015": "^6.24.0",
     "babel-preset-react": "^6.5.0",
     "babel-register": "^6.9.0",
     "express": "^4.13.4",

server.js

@@ -1,5 +1,5 @@
 require('babel-register')({
-    presets: ['react']
+    presets: ['react', 'es2015']
 });
 
 var express = require('express');

webpack.config.js

@@ -11,7 +11,7 @@ module.exports = {
                 exclude: /node_modules/,
                 loader: 'babel-loader',
                 query: {
-                    presets: ['react']
+                    presets: ['react', 'es2015']
                 }
             }
         ]