Provide consistency with NPM scripts

It trips me up each time that `npm run dev` exists but `npm run prod`
does not. This serves to fix that case, as well as providing consistency
in both directions `dev`/`development` and `prod`/`production`.

[Source](https://twitter.com/michaeldyrynda/status/846507021251690497)

package.json

@@ -5,7 +5,9 @@
     "watch": "cross-env NODE_ENV=development node_modules/webpack/bin/webpack.js --watch --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
     "watch-poll": "cross-env NODE_ENV=development node_modules/webpack/bin/webpack.js --watch --watch-poll --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
     "hot": "cross-env NODE_ENV=development node_modules/webpack-dev-server/bin/webpack-dev-server.js --inline --hot --config=node_modules/laravel-mix/setup/webpack.config.js",
-    "production": "cross-env NODE_ENV=production node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js"
+    "production": "cross-env NODE_ENV=production node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
+    "development": "$npm_package_scripts_dev",
+    "prod": "$npm_package_scripts_production"
   },
   "devDependencies": {
     "axios": "^0.15.3",