Remove unsupported Python 2.6, 3.2 and 3.3

[hugovk]

Reasons for dropping old ones

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

2.6

• https://snarky.ca/stop-using-python-2-6/
• http://www.curiousefficiency.org/posts/2015/04/stop-supporting-python26.html
• Current pip 9 deprecates Python 2.6 support, pip 10 won't support it (Drop support for Python 2.6? pypa/pip#3955)
• Not much PyPI traffic (June 2016) Deprecate/Drop Support for Python 3.3? pypa/pip#3796

3.2

• pip 8 no longer supports Python 3.2 (link)
• Coverage 4 no longer supports Python 3.2 (link)
• Requests no longer supports Python 3.2
• Virtually no PyPI traffic (June 2016) Deprecate/Drop Support for Python 3.3? pypa/pip#3796

3.3

• pip 10 will deprecate Python 3.3 support, pip 11 won't support it (Deprecate/Drop Support for Python 3.3? pypa/pip#3796)
• Very little PyPI traffic (June 2016) Deprecate/Drop Support for Python 3.3? pypa/pip#3796

[hugovk]

Here's the pip installs for pronouncing from PyPI for the last year, showing virtually no 2.6 or 3.3, and no 3.2 (I've no idea what that single 2.8 is!):

$ pypinfo -d 365 --percent --pip pronouncing pyversion
python_version percent download_count
-------------- ------- --------------
2.7              60.9%          1,005
3.5              18.8%            310
3.6              14.8%            244
3.4               5.3%             88
2.6               0.1%              2
3.3               0.1%              1
2.8               0.1%              1