python: mypy: use --fast-parser not with Windows (#998)
python: mypy: use --fast-parser not with Windows (#998)

Fixes https://github.com/neomake/neomake/issues/997.
neomake/neomake,bonds/neomake,euclio/neomake,neomake/neomake,nerdrew/neomake,nerdrew/neomake,euclio/neomake,bonds/neomake,codeinabox/neomake