options to pass test-framework and coffee to the createGenerator in test-helper

This will help to pass options to createGenerator in test

```js
var app = helpers.createGenerator('backbone:app', [
      '../../app', [
        helpers.createDummyGenerator(),
        'jasmine:app'
      ]
    ], {args: ['hello'], options: {'test-framework': 'jasmine'}});

```

This fix is also backward compatible, so won't break the existing tests for other generators.

Thanks.