Update README.md to show python dependencies about python-csr

[tlcowling]

I just tried it on Ubuntu 14.04 too but looks like pyOpenSSL is part of the python distribution

So I guess its arguable that given the differences in OS and the way people manage dependencies with python that maybe you could expect the user to figure it out themselves?

[cottonbeckfield]

The OpenSSL library is in the Linux version of python already.

I would believe this to be an OS specific issue. I program on a Mac, and this particular script did not use virtualenv and I didn't have an issue with needing to install pyOpenSSL. Your version of python may not have been compiled with the OpenSSL support; https://docs.python.org/3.4/library/ssl.html

I don't mind making a note that it may be needed, but that might be digging a bit deep.

[tlcowling]

I looked a bit more, I see that there are two standard python openssl libraries, one is ssl the other is pyOpenSSL.

My current python 2.7.10 was brew installed, the import OpenSSL doesn't work until I pip install pyOpenSSL, however I also have python 2.6.9 installed where import OpenSSL does work, so it appears to be down to python versions as you suggested

TL;DR
With standard python distributions, there doesn't seem to be a problem, if you want to use Python 2.7.10 in Mac OS X you need to pip install pyOpenSSL

[cottonbeckfield]

In a future update, I will have a note of what version of Python I used, and also some side FAQs for additional help for those who might be using alternative versions.

Thanks for looking into it.