minor: new codeclimate badge

Author: Brandon Black

README.md

@@ -2,7 +2,7 @@
 
 [travis-img]: https://secure.travis-ci.org/mongodb/mongo-ruby-driver.png
 [travis-url]: http://travis-ci.org/mongodb/mongo-ruby-driver
-[codeclimate-img]: https://codeclimate.com/badge.png
+[codeclimate-img]: https://codeclimate.com/github/mongodb/mongo-ruby-driver.png
 [codeclimate-url]: https://codeclimate.com/github/mongodb/mongo-ruby-driver
 [jenkins-img]: https://jenkins.10gen.com/job/mongo-ruby-driver/badge/icon
 [jenkins-url]: https://jenkins.10gen.com/job/mongo-ruby-driver/