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)
Looks like [`org_teams`](https://github.com/octokit/octokit.rb/blob/master/lib/octokit/client/organizations.rb#L204) uses `paginate`.