Only uglify in production.

.npmignore

@@ -0,0 +1,3 @@
+node_modules
+npm-debug.log
+package-lock.json

webpack.config.js

@@ -1,8 +1,9 @@
 'use strict'
 
-var path = require('path')
-var webpack = require('webpack')
+const path = require('path')
+const webpack = require('webpack')
 const UglifyJSPlugin = require('uglifyjs-webpack-plugin');
+const production = process.argv.indexOf('-p') !== -1
 
 module.exports = {
   devtool: 'source-map',
@@ -16,9 +17,9 @@ module.exports = {
     sourceMapFilename: '[name].js.map',
     publicPath: '/ipfs/'
   },
-  plugins: [
+  plugins: production ? [
     new UglifyJSPlugin({sourceMap: true})
-  ],
+  ] : [],
   module: {
     loaders: [
       {