Update build for gh-pages

Author: alex3165

example/package.json

@@ -6,7 +6,7 @@
   "homepage": "http://alex3165.github.io/react-mapbox-gl",
   "scripts": {
     "start": "cross-env NODE_ENV=dev node dev.server.js",
-    "build": "cross-env NODE_ENV=prod webpack",
+    "build": "cross-env NODE_ENV=prod webpack && cp dist/index.html dist/demos.html",
     "predeploy": "npm run build",
     "deploy": "gh-pages -d dist"
   },

example/webpack.config.js

@@ -13,7 +13,7 @@ var output = {
 // Add more files to copy to the dist folder (Eventually an assets folder)
 var toCopy = [
   { from: 'index.html' },
-  { from: 'style.css' },
+  { from: 'style.css' }
 ];
 
 var plugins = [