Teams pagination fix

* Fixes failing `GithubApi#find_team` when there are more than 30 teams
* Fetches 100 teams per page
* Iterates through all the pages
* It doesn't look very nice, but that's the suggested solution (https://github.com/octokit/octokit.rb/issues/517)
Prefer double-quoted strings unless you need single quotes to avoid extra backslashes for escaping.