tests: Have bad point to a file that’s definitely not a module, as it…

… was causing by issues in browserify related to: browserify/browserify#1030

fixtures/app/badapp.js

@@ -1,4 +1,4 @@
-var foo = require('foo');
+var foo = require('not-a-module');
 
 module.exports = function () {
     var x = 1;