no-unresolved https://github.com/benmosher/eslint-plugin-import/blob/master/docs/rules/no-unresolved.md
After installing eslint-import-resolver-webpack
eslint-import-resolver-webpack
The problem is that your webpack config is written in ES6 format, which doesn't play well with eslint-import-resolver-webpack.
So, you either refactor your webpack.config.js using ES5 syntax, or you get rid of eslint-import-resolver-webpack.
webpack.config.js
See here for the full solution: eslint plugin docs