CLIENTS-115: Use pyenv for multiple Python versions and tox to test them

[hazen]

Traditionally we've targeted only Python 2.7.x as our supported build version. In fact the native Ubuntu 12.04 LTS version 2.7.3 is the only one tested on buildbot. Now we'll use pyenv to virtualize 4 versions and actually test all of them both with and without security:

• 2.6.9
• 2.7.9
• 3.3.6
• 3.4.2

The real downside is, naturally, that the tests will take 4x longer, but this way we can catch changes which break one platform or another.

NOTE: Because of the older version of OpenSSL installed on the builder we need to allow older TLS versions to be supported in Riak since the Python 3 versions use the builtin ssl library instead of PyOpenSSL.

[christophermancini]

So, I ran into a problem with hard links and virtual box file sharing. I had to place the following at the beginning of the setup.py in order to complete the tox run.

if os.environ.get('USER','') == 'vagrant':
    del os.link

The code looks good and I was able to run the tests against all 4 target versions of python. I would consider adding the above to the setup.py to handle the edge case I ran into using a Virtual Box vm as my test server.

[christophermancini]

👍f9acd6e

[hazen]

@borshop merge

[christophermancini]

👍 f9acd6e

[hazen]

@borshop merge

[hazen]

@christophermancini I had to wack the builder a couple of times, but looks like this should work.

[christophermancini]

👍 ede2838

[hazen]

@borshop merge