Wheel-compatible conditional requirements

[nsoranzo]

See https://hynek.me/articles/conditional-python-dependencies/ for a background explanation.

The fallback for setuptools < 18 is inspired by https://gitlab.com/pycqa/flake8/blob/master/setup.py

[codecov]

Codecov Report

Merging #330 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #330   +/-   ##
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  Coverage   91.01%   91.01%           
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  Files           1        1           
  Lines        1636     1636           
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  Hits         1489     1489           
  Misses        147      147

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[tleonhardt]

Thanks for the PR Nicola!

It looks good to me, but I'm relatively ignorant of the new setuptools features. We will make sure they work OK when it comes time for the next release.

I don't think we normally release as a wheel, though I'm honestly not sure ...

[tleonhardt]

I wasn't familiar with this syntax within setuptools for conditional dependencies.

[nsoranzo]

@tleonhardt Thanks for the merge!

I don't think we normally release as a wheel, though I'm honestly not sure ...

Unfortunately not yet: https://pypi.python.org/pypi/cmd2

It is very simply and you can easily automate it with a Makefile:

$ python setup.py sdist
$ python setup.py bdist_wheel
$ twine upload dist/*

You just need recent versions of pip, setuptools, twine and wheel installed.