Check format in CI

Author: davidmreed

.github/workflows/rust.yml

@@ -21,6 +21,8 @@ jobs:
       run: cargo check --verbose
     - name: Clippy
       run: RUSTFLAGS=-Dwarnings cargo clippy --all-targets --all-features
+    - name: Format
+      run: cargo fmt --all --check
     - name: Unit Tests
       run: cargo test --verbose
   build: