add support for reading sasslintConfig from package.json

[chrisdrackett]

sass-lint lets you add a link to your yml config in package.json (https://github.com/sasstools/sass-lint#configuring). It would be great if linter-sass-lint could look here when looking for the config file.

[DanPurdy]

Hi @chrisdrackett yeah that's a bit of an oversight on my part to be honest. Although i'm currently changing a few things with how the config file is loaded in sass-lint itself and the formats that can be used so i may hold off on this until that is done. 👍

[fluxsauce]

This would be lovely, as we're using a centralized sass-lint configuration across multiple projects. Thank you!

[atomboyd]

Yes please! 👍

[seanogdev]

Would be a great addition. We have a sass-lint config in our internal npm build package, being able to access that would be very useful