Fix Python 2.6 support

[justinfay]

No description provided.

[mbr]

Python2.6 is somewhat of an issue - it's very annoying to support, 2.7 has been out for two years now and I rarely run into it myself. Officially, it is not supported - you can tell by the absence of py26 in the tox environment list =).

I've been toying with the idea of adding py2.6 support (at least for one specific version of simplekv), as pyenv makes it somewhat easier to get ahold of old interpreter version. I haven't figured out if it's worth it though - why are you stuck with 2.6?

[justinfay]

Hi @mbr thanks for the response, I understand the pain of having to support 2.6 😠 In this particular case it is for deploying on RHEL 6.x where we must use the system Python version.

I opened this pull request as in the projects setup.py you have a section requiring additional requirements for python versions older than 2.7

if sys.version_info < (2, 7):
    tests_require = ['unittest2']
else:
    tests_require = []

so I assumed it was still desirable to support older versions. If you do not wish to support older versions I have no problem with you closing this pull request.