CI: Add GH actions workflow

.github/workflows/ci.yml

@@ -0,0 +1,37 @@
+name: CI
+
+on:
+  push:
+    branches: [ "develop", "release-candidate", "main" ]
+  pull_request:
+    branches: [ "develop", "release-candidate", "main" ]
+
+jobs:
+  unit-test:
+    name: Unit Test
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-go@v5
+      with:
+        go-version-file: "go.mod"
+    - name: Run ginkgo tests
+      run: go run github.com/onsi/ginkgo/v2/ginkgo -r --procs=3 --compilers=3 --randomize-all --randomize-suites --fail-on-pending --keep-going --race --trace helpers
+
+  check-pr-target-branch:
+    if: github.event_name == 'pull_request'
+    name: Check PR target branch
+    runs-on: ubuntu-latest
+    steps:
+    - name: Fail if target branch is main
+      run: |
+        if [ "${{ github.event.pull_request.base.ref }}" == "main" ]; then
+          echo "Pull requests should not target 'main' branch."
+          exit 1
+        fi
+    - name: Fail if target branch is release-candidate
+      run: |
+        if [ "${{ github.event.pull_request.base.ref }}" == "release-candidate" ]; then
+          echo "Pull requests should not target 'release-candidate' branch."
+          exit 1
+        fi