improve webpack config

webpack/build.package.js

@@ -0,0 +1,24 @@
+import ora from 'ora'
+import webpack from 'webpack'
+import config from './webpack.package.config'
+
+const spinner = ora('Building …')
+
+export default new Promise((resolve, reject) => {
+	spinner.start()
+
+	webpack(config, (error, stats) => {
+		if (error) {
+			return reject(error)
+		}
+
+		if (stats.hasErrors()) {
+			process.stdout.write(stats.toString() + "\n");
+			return reject(new Error('Build failed with errors.'))
+		}
+
+		return resolve('Build complete.')
+	})
+})
+.then(success => spinner.succeed(success))
+.catch(error => spinner.fail(error))