Update dependencies

[lukemelia]

This will help people (like me!) trying to upgrade ember in their apps

[dfreeman]

Thanks for the PR @lukemelia! I'm certainly not opposed, but I'm a bit curious (beyond just good maintenance practice) why this is necessary. None of these dependencies should conflict with or prevent upgrading Ember, should they?

And taking a step slightly further back, I'm not sure this plugin is really needed today, at least for the GitHub Actions happy path. All the nonsense it does with setting up ssh-agent and configuring a deploy key was necessary in third party CI services, but in Actions most of the machinery is already in place in the runner to be able to push new commits.

I believe all that's necessary is setting user.name and user.email, which you can either do with https://github.com/marketplace/actions/setup-git-user or by hand via git config (as mentioned in that action's docs).

[lukemelia]

IIRC, there was a node engine requirement incompatibility somewhere in there.

Great point about github actions setup, though! The project this is used in is on CircleCI. Probably not too hard to deal with it per Circle's docs too though.

[dfreeman]

The current node requirement includes >= 7.* which, while super outdated, should still accommodate anything newer 🙂

[lukemelia]

I'll confirm if this is needed or not in my in-progress upgrade