Update actions/checkout action to v2

[renovate]

This PR contains the following updates:

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

---

Release Notes

actions/checkout

v2

Compare Source

• Fix default branch resolution for .wiki and when using SSH

---

Renovate configuration

📅 Schedule: At any time (no schedule defined).

🚦 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, check this box

---

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

[renovate]

Renovate Ignore Notification

As this PR has been closed unmerged, Renovate will ignore this upgrade and you will not receive PRs for any future 2.x releases. However, if you upgrade to 2.x manually then Renovate will then reenable updates for minor and patch updates automatically.

If this PR was closed by mistake or you changed your mind, you can simply rename this PR and you will soon get a fresh replacement PR opened.