dev-python/pytest-runner is used only to run tests via 'setup.py pytest' which isn't happening in the ebuild. I'm guessing upstream hardcodes the dep in setup_requires. Please strip it.
Done, thanks. Also removed the deprecated pycrypto dependency. I have left -r2 in there just in case for a little while. Also, if you use this feel free to add yourself to metadata. I no longer use it at work (bare requests or curl is more convenient) so it doesn't get the scrutiny it should get.