Make build script bail on failure

examples/filebrowser/package.json

@@ -2,8 +2,9 @@
   "private": true,
   "name": "filebrowser-example",
   "dependencies": {
-    "jupyter-js-ui": "file:../..",
+    "codemirror": "^5.12.0",
     "jupyter-js-services": "^0.5.1",
+    "jupyter-js-ui": "file:../..",
     "jupyter-js-utils": "^0.3.1",
     "phosphor-arrays": "^1.0.6",
     "phosphor-codemirror": "0.0.1",

scripts/buildexamples.js

@@ -14,6 +14,7 @@ for (var i = 0; i < dirs.length; i++) {
       console.log('Error code: ' + error.code);
       console.log('Signal received: ' + error.signal);
       console.log('Child Process STDERR: ' + stderr);
+      process.exit(1);
      }
      console.log('Child Process STDOUT: ' + stdout);
   });