Neutrino 9 is our largest release ever, and includes upgrades to
webpack 4, Babel 7 and ESLint 6, along with significant performance
improvements.

The biggest breaking change is the necessity to use external tools
*alongside* Neutrino, i.e. webpack, ESLint, Jest, Karma, and others'
native CLIs will be used in tandem with Neutrino rather than being used
internally via their APIs. This fixes many bugs, gives more control over
how these tools are run and means usage of new features is no longer
blocked on Neutrino changes to support them.

Please see the migration guide for how to update:
https://neutrinojs.org/migration-guide/#neutrino-v8-to-v9

If you encounter any bugs, have questions or spot improvements that can
be made to the migration guide/docs - we'd love to hear from you:
https://github.com/neutrinojs/neutrino/issues