🧪 Cache rust on CI (#2)

Author: chrisjsewell

.github/workflows/tests.yml

@@ -20,6 +20,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
+    - name: install rust stable
+      uses: dtolnay/rust-toolchain@stable
+    - name: cache rust
+      uses: Swatinem/rust-cache@v2
     - name: Build
       run: cargo build --verbose
     - name: Run tests