test semver github action

.github/workflows/semver_action.yml

@@ -0,0 +1,27 @@
+name: Cargo semver check
+
+on:
+  pull_request:
+  push:
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  cargo_semver_checks:
+    name: Cargo SemVer Checks
+    runs-on: ubuntu-latest
+    # Make this check mandatory for release branches.
+    continue-on-error: ${{ !startsWith(github.base_ref, 'release/') }}
+    strategy:
+      matrix:
+        toolchain:
+          - stable
+    steps:
+      - name: Check out head (${{ github.head_ref }})
+        uses: actions/checkout@v3
+      - name: Check semver for all crates from my-workspace
+        uses: obi1kenobi/cargo-semver-checks-action@v2
+        with:
+          manifest-path: ${{ github.workspace }}/Cargo.toml  # or just semver/my-workspace/
+#          package: cedar-policy-core