Newer versions of pylint will now check your code as you type. Older
versions will still only check the file on disk.
Co-authored-by: Oliver Wiegers <oliver.wiegers@gmail.com>
`lint_file` can now be computed dynamically with a callback function,
which can return a deferred result, as per `ale#command#Run`. This
allows linters to dynamically switch between checking files on disk,
or checking code on the fly.
Some tests have been fixed on Windows.