CVE issued for socketpair.py

Hello, 

The [file socketpair.py](https://github.com/dpkp/kafka-python/blob/master/kafka/vendor/socketpair.py) has a CVE issued as of yesterday.
Please see [original gist](https://gist.github.com/geertj/4325783) for details.

Thank you, 