closes#1396
- moved core/test/unit/api* to core/test/integration/api/
- moved core/test/integration/model* to core/test/integration/model/
- moved core/test/unit/utils to core/test/utils
- moved core/test/unit/fixtures to core/test/utils/fixtures/
- changed gruntfile.js to execute api tests with target 'integration'
closes#1189
- added tests
- added request module
- added status codes to API calls
- fixed return values of API calls
- fixed that drafts caused an error when being deleted
- fixed X-Invalidate-Cache headers
- moved testUtils.js to utils/index.js
