fix: throw on 304

fix: octokit.apps.getInstallations() does not throw TypeError

fix(typescript): update types to reflect client option changes (octok…

…it#815)

fix(typescript): agent client option is optional (octokit#803)

fix: proxy without setting baseUrl (octokit#812)

fix: clarify deprecation warning for `protocol`, `bost`, `port` and `…

…pathPrefix`

feat: options.baseUrl (octokit#807)

### Deprecations

Client options

- `options.headers`
- `options.port`
- `options.pathPrefix`
- `options.host`

are now replaced by `options.baseUrl`

fix: set error.headers if present

fix: remove obsolete github.search.email() API (octokit#795)

fix: remove milestone from issue