* Updated lock-file to fix https://github.com/npm/cli/issues/4859.
* Updated integration-tests to webpack 5 to fix
https://github.com/webpack/webpack/issues/14532.
* Added `mode` to webpack-integration-tests to avoid
the warning `The 'mode' option has not been set...`.
* Replaced outdated `grunt-bg-shell`-package to get rid of
coffee-script warnings