Add missing fields of HookCommit

[jkarni]

Issue reference: #89

Submission Checklist:

• [x] Have you followed the guidelines in our Contributing document (for example, is your tree a clean merge)?
• [x] Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• [x] Does your submission build?
• [x] Does your submission pass tests?
• [x] Have you run lints on your code locally prior to submission? [hlint]
• [x] Have you updated all of the cabal/nix infrastructure?
• [x] Is this a breaking change? Have you discussed this? [It is not breaking unless new fields are always considered breaking]

[kvanbere]

Thanks, is there any documentation from GitHub that backs this? Maybe we should link it here for future reference.

[kvanbere]

@ashercuedo

[ashercuedo]

Thanks for the pull request, I'll jump on it as soon as I can 👍

[jkarni]

Thanks, is there any documentation from GitHub that backs this? Maybe we should link it here for future reference.

The main source is still the push event, which is already referenced in the PushEvent type. It's not referenced directly in HookCommit, but as far as I can tell this is actually a common datatype for several different similar fields in GitHub.