Allow styles an ability to override the actual checks

[pgjones]

This is specifically helpful to allow the edited style to have an optional newline between import and form X import lines without triggering a I202 error.

In a more general sense this should allow for more advanced styles.

[pkatseas]

This looks really good @pgjones, thanks for taking the time to look into it!

I'm afraid there's still one example that's not covered under this implementation:

from a_repo import settings

from .exceptions import AnError
from .a_module import MyClass
from ..base import BaseClass

The empty line between the imports is still causing an I202, even though the following entry is in our setup.cfg and from a_repo imports should(?) be considered to be in the same group as relative (from .) imports:

[flake8]
application-import-names = a_repo

Edit: I'm more than happy to fix this myself if you don't mind an extra PR by the way.

[pgjones]

@pkatseas I think this then represents the actual edited style, can you take a look at the complete example and note if any of it is not the edited style?

[pgjones]

@pkatseas Is this style correct now?

[janrito]

This is brilliant, thanks @pgjones. It works as expected