Drop support for Python 2.6, 3.2 and 3.3, as per wheel's official sup…

[nir0s]

…port

• Drop support for python versions not supported by the latest version of wheel (2.6, 3.2, 3.3).
• State that in the README.
• State in the README that to use Wagon in 2.6, 3.2 and 3.3, you should use v0.6.1 and below.

[nir0s]

@funkyHat @mcouthon

[hugovk]

Should this 3.3 stuff be removed too?

[hugovk]

Maybe add this?

'Programming Language :: Python :: 2',

[hugovk]

By the way, here's the pip installs for wagon from PyPI for the last month, showing low numbers for 2.6 and none for 3.2 or 3.3:

$ pypinfo --percent --pip wagon pyversion
python_version percent download_count
-------------- ------- --------------
2.7              76.7%          5,505
3.4              21.0%          1,511
2.6               2.1%            152
3.6               0.1%              7
3.5               0.0%              3
3.7               0.0%              1

[nir0s]

Good point @hugovk. I'll address this. @mxmrlv, are we going to address this PR?

[hugovk]

Here we go:

python_requires='>=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*',

[nir0s]

hehe. wonderful.