eslint-plugin-import: The development-environment doesn't work on windows

When trying to test the module on a windows platform, weird errors appear as seen in AppVeyor: https://ci.appveyor.com/project/benmosher/eslint-plugin-import/builds/33096831/job/gg7jvh5ehfb4s9ag

This also might be because the dependencies weren’t updated for a long time and don’t support node 14.x.