feat(package): update extract-text-webpack-plugin to 4.0.0-beta.0
feat(package): update extract-text-webpack-plugin to 4.0.0-beta.0

fabric8io/fabric8-ui,fabric8io/fabric8-ui,fabric8-ui/fabric8-ui,fabric8-ui/fabric8-ui,fabric8io/fabric8-ui,fabric8io/fabric8-ui,fabric8-ui/fabric8-ui,fabric8-ui/fabric8-ui,fabric8io/fabric8-ui,fabric8-ui/fabric8-ui