make coverage 100% again

I've updated entity test to make coverage 100% again, please let me know if any correction ;).
I've added 'coverage-html' into data/test-html-report to make sure it 100% in my local and in the future, we can make it as reference to make always 100%.
![screen shot 2014-12-09 at 1 13 16 pm](https://cloud.githubusercontent.com/assets/459648/5353099/2a772c54-7fa5-11e4-810d-16278fd27e6c.png)
 
Thank you.