Drop support for EOL Python 2.6 and 3.3

[hugovk]

Python 2.6 and 3.3 are EOL and no longer receiving security updates. They're also little used.

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

Here's the pip installs from PyPI for jsonpointer for last month, showing very low fractions for 2.6 and 3.3:

python_version	percent	download_count
2.7	92.5%	274,004
3.6	3.0%	8,889
3.5	2.5%	7,435
3.4	1.9%	5,673
3.3	0.1%	156
2.6	0.0%	113
3.7	0.0%	63
None	0.0%	9

Source: pypinfo --start-date -45 --end-date -15 --percent --pip --markdown jsonpointer pyversion

[stefankoegl]

Thanks!

Reminder to myself. I'll also have to remove support for 3.3 from stefankoegl/python-json-patch, which depends on python-json-pointer.

[hugovk]

There you go! ==> stefankoegl/python-json-patch#81

[stefankoegl]

Awesome :)