Remove build directory without ending up in trash

This is frustrating with shells like `fish` that track directory moves

scripts/build.js

@@ -14,7 +14,9 @@ var webpack = require('webpack');
 var config = require('../config/webpack.config.prod');
 var paths = require('../config/paths');
 
-rimrafSync(paths.appBuild);
+// Remove all content but keep the directory so that
+// if you're in it, you don't end up in Trash
+rimrafSync(paths.appBuild + '/*');
 
 webpack(config).run(function(err, stats) {
   if (err) {