add expiry to key capabilities

[dizzzan]

Need key expiry in the terraform provider, and I saw it was not yet added to the client pkg, but is available in the API.
Will open separate PR for terraform provider, if this is approved.
Thanks!

[DentonGentry]

This repo and the terraform repo require signed commits using either GPG or SSH keys. Are you set up to do that? If not, I can generate a PR with this change and sign it.

[dizzzan]

This repo and the terraform repo require signed commits using either GPG or SSH keys. Are you set up to do that? If not, I can generate a PR with this change and sign it.

Ah, just noticed that, sorry. I don't have signing set up on this computer. I can amend the PR later (I think pushing a new signed commit will suffice?), but feel free to generate a separate one instead. I also just created tailscale/terraform-provider-tailscale#175 which will have the same issue :/

[dizzzan]

@DentonGentry pushed a signed commit, but it seems that didn't pass the check.

[DentonGentry]

There are two commits in this PR and the first is not signed, so it is rejected. I think you want to remove the second, signing commit: git reset --hard HEAD^1

Then sign the first commit: git commit --amend -S

Then force push it to the PR: git push -f

[dizzzan]

Bingo, thanks :)

[davidsbond]

Looks like this field has been added in the incorrect place based on #35 and the API documentation. Have added an example here