Use require.resolve to allow nested extend

[frenzzy]

Continues #582

If you will start to use config { extends: ["eslint-config-airbnb"] } in the project a together with the following peer dependencies eslint-plugin-import, eslint-plugin-jsx-a11y, eslint-plugin-react, then you will receive an error if you will try to extend this config in the project b:

/projects/a/.eslintrc Referenced from: /projects/b/.eslintrc
[Error] Failed to load plugin /projects/a/node_modules/eslint-plugin-jsx-a11y/lib/index.js: Cannot find module 'eslint-plugin-/projects/a/node_modules/eslint-plugin-jsx-a11y/lib/index.js' Referenced from: /projects/b/.eslintrc

This issue is probably actual for monorepos. For example it is not cool to install import, jsx-a11y and react plugins into node_modules folder of the each project. This change helps to avoid it.

[ljharb]

I'm afraid this will break a lot of things.

These plugins are peer dependencies - they are required to be installed in the top-level project.

To change this, eslint itself would have to change - it's not something a shared config can work around.