Python 2.6 is deprecated

[j-maas]

As seen in the build at https://travis-ci.org/mswart/pyopenmensa/jobs/350746974#L443, there is a deprecation warning for Python 2.6.

I would suggest removing support and build for that version.

[hugovk]

👍

Python 2.6 has been EOL for over 4 years and is no longer supported by the core Python team.

How about also dropping support for 3.2 and 3.3? They're also EOL:

And not used. Here's the pip installs for pyopenmensa from PyPI for last year:

python_version	percent	download_count
3.4	37.68%	26
2.7	28.99%	20
3.6	23.19%	16
3.5	10.14%	7

Source: pypinfo --start-date -372 --end-date -8 --percent --pip --markdown pyopenmensa pyversion

https://en.wikipedia.org/wiki/CPython#Version_history

[hugovk]

Feedback welcome on PR #14.