Update actions/checkout action to v2 - autoclosed

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	major	v1 -> v2

---

Release Notes

actions/checkout

### [`v2`](https://togithub.com/actions/checkout/blob/HEAD/CHANGELOG.md#v231) [Compare Source](https://togithub.com/actions/checkout/compare/v1...v2) - [Fix default branch resolution for .wiki and when using SSH](https://togithub.com/actions/checkout/pull/284)

---

Configuration

📅 Schedule: "every weekend" in timezone America/Los_Angeles.

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• [ ] If you want to rebase/retry this PR, click this checkbox.

---

This PR has been generated by WhiteSource Renovate. View repository job log here.