webpack-isomorphic-tools::development() method deprecated

Got this error after running `npm run start-dev`
```bash
[webpack-isomorphic-tools] [error] `.development()` method is now deprecated
(for server-side instance only, not for webpack plugin instance) and has no effect.
Set up a proper `process.env.NODE_ENV` variable instead: it should be
"production" for production, otherwise it assumes development.
The currently used mode is: development.
`process.env.NODE_ENV is: development
```

unsure if this is webpack-isomorphic-tools or this repo or what not it's late