Excluding files/folders in .gitignore from ava-files

[transcranial]

See #1228 for an example as to why this would be helpful.

[sindresorhus]

Just to add some description, this issue is about ignoring files matching glob patterns defined in .gitignore (not ignoring the .gitignore file itself). Ideally, the functionality would be added to globby as an option so it could benefit many other projects, but we would also consider adding it here if it's too hard to generalize.

[novemberborn]

It should still be possible to explicitly select files that are otherwise ignored through .gitignore.

[sindresorhus]

Globby now has a gitignore option.

[novemberborn]

It should still be possible to explicitly select files that are otherwise ignored through .gitignore.

Does Globby take care of that? Otherwise overriding exclusion patterns is too difficult. But maybe we can support it as a configuration option.