Use webpack CLI instead of gulpfile.js

webpack.config.main.js

@@ -0,0 +1,20 @@
+module.exports = {
+  entry: './src/main.js',
+  output: {
+    filename: './dist/main.js'
+  },
+  module: {
+    loaders: [{
+      test: /\.json$/,
+      loader: 'json'
+    }]
+  },
+  node: {
+    __filename: false,
+    __dirname: false
+  },
+  target: 'electron-main',
+  externals: {
+    remote: true // for electron-connect
+  }
+};