Add smoke tests after deployment

After each deployment there should be at least very basic "smoke test" that verify that basic features are working: new dashboard can be created, some cities can be found and added to the dashboard then removed, comments and be added, changed and deleted.

Ideally such e2e (end-to-end) test should end with posting URL of created dashboard to MS Teams channels where anyone from the team can open it and inspect visually (to be extracted as new task once smoke test exists).