Bump postcss and @angular-devkit/build-angular in /frontend/src/main/ngx#19

dependabot[bot] wants to merge 10 commits intomainontimize/ontimize-boot-tutorial:mainfrom

dependabot/npm_and_yarn/frontend/src/main/ngx/postcss-and-angular-devkit/build-angular-8.4.21ontimize/ontimize-boot-tutorial:dependabot/npm_and_yarn/frontend/src/main/ngx/postcss-and-angular-devkit/build-angular-8.4.21Copy head branch name to clipboard