Fixing 404 in tests

```bash
$ npm run test-watch

> imager.js@0.1.0 test-watch /Users/oncletom/workspace/Imager.js
> karma start

INFO [karma]: Karma v0.10.8 server started at http://localhost:9876/
INFO [launcher]: Starting browser PhantomJS
INFO [PhantomJS 1.9.2 (Mac OS X)]: Connected on socket EyFeM7rUO8DKTKPou59V
WARN [web-server]: 404: /base/Demo%20-%20Grunt/Assets/Images/Generated/A-320.jpg
```