Replace deprecated babel-eslint with @babel/eslint-parser
Replace deprecated eslint-loader with eslint-webpack-plugin
Update other plugins, resolving several opened security reports.
Signed-off-by: Kevin Decherf <kevin@kdecherf.com>
Update javascript deps to latest version.
Rebuild assets
- Keep `stylehint` in a lower version because starting at v9.0.0 it generates too much errors. We might fix them later.
- Don't touch `materialize-css` to avoid too much side effect. We might update it later (to 1.0.0).
