disable for certain file extensions

I would like to be able to disable ide-python for files matching a certain Glob, a la [Linter](https://atom.io/packages/linter).

For example, [snakemake](https://snakemake.readthedocs.io/en/stable/) uses a python-based language (and thus [MagicPython](https://atom.io/packages/magicpython) in Atom), but pycodestyle and pyflakes don't know how to handle it. If I could disable ide-python for files called "Snakefile" and ending in ".smk", that would be very useful.

No files or tests are named. Start by reviewing how ide-python selects files and exposes settings, then compare the requested glob-based exclusions for Snakefile and *.smk; done means those files no longer invoke pycodestyle or pyflakes while normal Python files still do.

Written by the indexing model from the issue text.