chore: add test workflow

Run tests in PR checks.

.github/workflows/test.yml

@@ -0,0 +1,18 @@
+name: Test
+
+on:
+  pull_request:
+    branches: [ "main" ]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: Build
+      run: cargo build --verbose --workspace
+    - name: Run tests
+      run: cargo test --verbose --workspace