Replace to new CodeClimate badge that shows score

| before | after |
| --- | ---|
| [![Code Climate](https://codeclimate.com/badge.png)](https://codeclimate.com/github/jnicklas/turnip) |  [![Code Climate](https://codeclimate.com/github/jnicklas/turnip.png)](https://codeclimate.com/github/jnicklas/turnip) |