Don't double-paginate GitHub responses

Oktokit::Client is always initialized with `auto_paginate: true`,
so no additional pagination work is necessary. In fact, paginating
from Hound caused lists with > 100 results to return duplicate
entries and perform redundant work.
I've actually added `paginate` to Octokit for `pull_request_comments`. But we haven't updated to that version of Octokit yet. Thoughts on doing that as part of this PR?