I needed to install the following from wheels (.whl file):

• Twisted – Twisted-15.5.0-cp27-none-win32.whl
• lxml – lxml-3.5.0-cp27-none-win32.whl

and upgrade cryptography

pip install cryptography –upgrade

Get the wheels from http://www.lfd.uci.edu/~gohlke/pythonlibs/