Avoid including full Lodash build (#45)

* Transform Lodash imports via Babel plugin (build: 513 kB -> 450 kB)

bin/build.js

@@ -0,0 +1,24 @@
+#!/usr/bin/env node
+
+// webpack.config.prod.js checks this.
+process.env.NODE_ENV = 'production';
+
+// Load the create-react-app config.
+const webpackConfigProd = require( 'react-scripts/config/webpack.config.prod' );
+
+// Modify the config according to our needs.
+
+const babelLoader = webpackConfigProd.module.loaders[ 0 ];
+if ( babelLoader.loader !== 'babel' ) {
+	console.error( webpackConfigProd.module.loaders );
+	throw new Error( 'Couldn\'t find the babel loader config.' );
+}
+
+babelLoader.query.plugins = ( babelLoader.query.plugins || [] )
+	.filter( pluginName => pluginName !== 'lodash' )
+	.concat( 'lodash' );
+
+console.log( 'Added lodash babel plugin to build' );
+
+// Run the build.
+require( 'react-scripts/scripts/build' );

package.json

@@ -4,6 +4,7 @@
   "private": true,
   "devDependencies": {
     "babel-eslint": "^7.1.0",
+    "babel-plugin-lodash": "^3.2.9",
     "deep-freeze": "0.0.1",
     "eslint": "^3.9.1",
     "eslint-plugin-react": "^6.6.0",
@@ -33,10 +34,10 @@
   },
   "scripts": {
     "start": "react-scripts start",
-    "build": "npm run lint && react-scripts build",
+    "build": "npm run lint && node bin/build.js",
     "test": "npm run lint && react-scripts test --env=jsdom",
     "eject": "react-scripts eject",
-    "lint": "eslint --ext js,jsx .eslintrc.js src/",
+    "lint": "eslint --ext js,jsx .eslintrc.js src/ bin/",
     "deploy": "npm run build && surge -p ./build -d wpconsole.surge.sh"
   }
 }