Enforce cargo fmt in CI

Author: kevinmehall

.github/workflows/rust.yml

@@ -8,6 +8,12 @@ env:
   CARGO_TERM_COLOR: always
 
 jobs:
+  format:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Cargo Fmt
+        run: cargo fmt --all -- --check
   build:
     name: Rust ${{matrix.rust}}
     strategy: