Auto merge of #2531 - imbsky:actions-cache-v2, r=JohnTitor
Auto merge of #2531 - imbsky:actions-cache-v2, r=JohnTitor

Bump actions/cache from v1 to v2

We just released v2. That includes a lot of improvements.
https://github.com/actions/cache/releases/tag/v2.0.0

rust-lang/crates.io,rust-lang/crates.io,rust-lang/crates.io,rust-lang/crates.io