Обновляем angular и зависимости.
npm install --save-dev @angular/{cli,compiler-cli}@6.0.0-rc.5
npm install --save-dev [email protected]
npm install --save @angular/{animations,common,compiler,core,forms,http,platform-browser,platform-browser-dynamic,router,service-worker}@6.0.0-rc.5
ng update @angular/cli --migrate-only --from=1.7.3
# DELETE .angular-cli.json