Drop support for EOL Python 3.4

[hugovk]

Here's a quick checklist that should be present in PRs:

• Make sure to include reasonable tests for your change if necessary

• We use towncrier for changelog management, so please add a news file into the changelog folder following these guidelines:

  • Name it $issue_id.$type for example 588.bugfix;

  • If you don't have an issue_id change it to the PR id after creating it

  • Ensure type is one of removal, feature, bugfix, vendor, doc or trivial

  • Make sure to use full sentences with correct case and punctuation, for example:

    Fix issue with non-ascii contents in doctest text files.
    

---

Python 3.4 is EOL and no longer receiving security updates (or any updates) from the core Python team.

Version	Release date	Supported until
2.7	2010-07-03	2020-01-01
3.4	2014-03-16	2019-03-16

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

The latest pytest 5.x series no longer supports it. More info: https://docs.pytest.org/en/latest/py27-py34-deprecation.html

It's also little used. Here's the pip installs for pytest-xdist from PyPI for September 2019:

category	percent	downloads
3.7	54.90%	902,956
3.6	23.28%	382,977
2.7	13.65%	224,458
3.5	7.43%	122,190
3.4	0.33%	5,401
null	0.29%	4,714
3.8	0.11%	1,839
2.6	0.01%	214
3.3	0.00%	60
3.2	0.00%	15
Total		1,644,824

Date range: 2019-09-01 - 2019-09-30

Source: pip install -U pypistats && pypistats python_minor pytest-xdist --last-month

[ssbarnea]

Rebase and drop it! I would like to see py34 being drop before py27.

[hugovk]

Updated!

[nicoddemus]

Thanks @hugovk!

[ssbarnea]

Ship it! ;)

[XVilka]

Should it be merged?