cmd task: Strip quotes from token on Windows

[ameily]

I found an issue related to #16 where, on Windows, a quoted token is being passed to the command still wrapped in quotes. This only happens on Windows because the shelx.split(posix=False) preserves them. You can verify this issue on Windows with the poethepoety test-quick task, which passes a quotes string to pytest and fails because the marker contains an invalid quote character:

Poe => pytest --cov=poethepoet -m "not slow"
# ... cut ...
ERROR: Wrong expression passed to '-m': "not slow": at column 1: unexpected character ""

I initially was seeing this with a call to cspell and have reproduced it with a small script / task.

# args.py
import sys
print(sys.argv)

# pyproject.toml
[tool.poe.tasks.args]
cmd = "python args.py \"hello world\" \"some/glob/**/*.py\""

The results of running the args task show that, on Windows, the quotes are preserved when they should be stripped.

$ poetry poe args
Poe => python args.py "hello world" "some/glob/**/*.py"
['args.py', '"hello world"', '"some/glob/**/*.py"']

I tried using some of the examples from #16 but I couldn't get them to work in my case, either the glob was being expanded by poe or the quote characters were being passed to the subprocess.

[ameily]

It looks like the Windows tests are failing because they expect the quoted behavior in stdout. If you're ok with my change, I'll update the tests and get them passing.

[nat-n]

Hi @ameily, thanks for working on this! If you fix the tests I'd be happy to merge it.

[ameily]

This should be good to go. Thanks for maintaining poe and being responsive! I useit for several Windows and Linux projects.