[gc-stack-deploy] Run unit tests in GitHub Actions on branch push

.github/workflows/unit-tests.yml

@@ -0,0 +1,18 @@
+name: Unit tests
+
+on:
+  push:
+
+jobs:
+  test-unit:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Run gc-stack-deploy unit tests
+        run: make -C caprover/tests test-unit

caprover/tests/README.md

@@ -14,12 +14,11 @@ setting up and tearing down a CapRover server).
 
 ## When to run Tests
 
-Since we have not automated running tests (e.g. in CI), we provide a simple recommendation:
+GitHub Actions runs **unit tests only**.  It cannot run e2e tests.
 
-* Run the tests locally for every change to `stack_deploy.py` or `stack.example.yaml`
-
-You probably do not need to run the tests when adding/modifying one-click app definitions,
-because that build step is in fact run automatically in CI.
+For every change to `gc-stack-deploy`, including the YAML file,
+and every change to one-click apps,
+run the E2E tests locally (`make -C caprover/tests all`)
 
 
 ## Prerequisites