Use rimraf as it handles edge cases

package.json

@@ -42,6 +42,7 @@
     "html-webpack-plugin": "^2.22.0",
     "json-loader": "^0.5.4",
     "postcss-loader": "^0.9.1",
+    "rimraf": "^2.5.3",
     "style-loader": "^0.13.1",
     "url-loader": "^0.5.7",
     "webpack": "^1.13.1",

scripts/build.js

@@ -10,14 +10,14 @@
 process.env.NODE_ENV = 'production';
 
 var path = require('path');
-var spawnSync = require('child_process').spawnSync;
+var rimrafSync = require('rimraf').sync;
 var webpack = require('webpack');
 var config = require('../webpack.config.prod');
 
 var isInNodeModules = 'node_modules' ===
   path.basename(path.resolve(path.join(__dirname, '..', '..')));
 var relative = isInNodeModules ? '../..' : '.';
-spawnSync('rm', ['-rf', relative + '/build']);
+rimrafSync(relative + '/build');
 
 webpack(config).run(function(err, stats) {
   if (err) {

scripts/graduate.js

@@ -9,6 +9,7 @@
 
 var fs = require('fs');
 var path = require('path');
+var rimrafSync = require('rimraf').sync;
 var spawnSync = require('child_process').spawnSync;
 
 console.log('Graduating...');
@@ -74,7 +75,7 @@ fs.writeFileSync(
 console.log();
 
 console.log('Running npm install...');
-spawnSync('rm', ['-rf', selfPath]);
+rimrafSync(selfPath);
 spawnSync('npm', ['install'], {stdio: 'inherit'});
 console.log();