$ pip install -v 'cffi>=1.4.1'
Skipping link http://172.29.236.100:8181/os-releases/11.2.10/cffi-1.5.2-cp27-cp27mu-linux_x86_64.whl (from http://172.29.236.100:8181/os-releases/11.2.10/); it is not compatible with this Python

$ python --version
Python 2.7.6