Installation Struct Missing for CheckRunPayload and CheckSuitePayload

[juliojimenez]

The installation ID allows us to check when the event is configured for and sent to a GitHub App.

References:

https://docs.github.com/en/developers/webhooks-and-events/webhook-events-and-payloads#webhook-payload-object
https://docs.github.com/en/developers/webhooks-and-events/webhook-events-and-payloads#webhook-payload-object-1

Pull Request: #128