Upgrade to latest @octokit/rest

[gr2m]

Related to danger/danger-js#983. Depends on https://github.com/octokit/rest.js/pull/1586.

You had the @octokit/rest version pinned before. I do not think that is necessary, but let me know if you prefer that

[orta]

This PR goes to your repo! - will pull it in manually

[orta]

Merged manually, should I wait for:

index.ts:1:10 - error TS2305: Module '"/Users/ortatherox/dev/danger/memfs-or-file-map-to-github-branch/node_modules/@octokit/rest/index"' has no exported member 'Octokit'.

1 import { Octokit } from "@octokit/rest"
           ~~~~~~~

Or will this work at runtime anyway?

[gr2m]

It will work at runtime anyway.

I've merged https://github.com/octokit/rest.js/pull/1586, the release resulting from the change will make TypeScript happy, too