Improvements for setup and login
Small improvements:
- Hide google/facebook button if it isn't configured (which is normal for non-production instance)
- Clean up promises for properly setup correct system preference
- Update tests for rely only on configurator to setup the instance**
There still hateoas_url and authentication policy that are later set. But this configuration is expected (like MailHost) since it depends on the site infrastructure and who is setuping it.