Find all the places that have not used in this gem

[ShockwaveNN]

All methods are listed here
https://api.onlyoffice.com/portals/basic

Maybe this project will be a help
https://github.com/ONLYOFFICE-QA/testing-api.onlyoffice.com/

I'm not sure, but maybe testing-api.onlyoffice.com has method that crawl api.onlyoffice.com/portals and save all existing methods in single json file

After that compare that file and methods listed in this gem and found out methods that are not used in gem - add rspec tests for them