Update to node-sass v4.9 due to Node v10

[mattsoltani]

With the recent release of node v10, node-sass was broken (see sass/node-sass#2345) including node-sass-magic-importer.
This has been fixed in the v4.9 release, so node-sass-magic-importer just needs to be updated to use this version to get the fix.

[maoberlehner]

Thanks for reporting this!

[mattsoltani]

@maoberlehner Thank you for fixing this already. It doesn't seem to be released yet. When do you expect to release the update?

[maoberlehner]

Hey @mattsoltani, I've just published a new release, but I don't think this should have any effect on you. node-sass was only a devDependency of the Monorepo, so the node-sass-magic-importer package does not (explicitly) depend on any specific version of node-sass anyway (as you can see here: https://github.com/maoberlehner/node-sass-magic-importer/blob/master/packages/node-sass-magic-importer/package.json).