Output the rust version for each build.

[markmandel]

This makes it easier to determine if issues are related to which Rust version is being run in CI.

Work on #281

[quilkin-bot]

Build Succeeded 🥳

Build Id: aaf48dae-16bb-4454-aa94-bae5cd4be1ba

To build this version:

git fetch [email protected]:googleforgames/quilkin.git pull/288/head:pr_288 && git checkout pr_288
cargo build

[markmandel]

SYAC

rustc 1.51.0 (2fd73fabe 2021-03-23)
binary: rustc
commit-hash: 2fd73fabe469357a12c2c974c140f67e7cdd76d0
commit-date: 2021-03-23
host: x86_64-unknown-linux-gnu
release: 1.51.0
LLVM version: 11.0.1

@XAMPPRocky this look like what you expected?

[XAMPPRocky]

@markmandel Yes though it makes how clippy was producing that warning more strange, but lets see if it happens again now with this.