Add semver checks to pipeline

Author: Iizuki

.github/workflows/publish.yml

@@ -48,8 +48,24 @@ jobs:
       - name: Run tests
         run: cargo test --verbose
 
+      # Check that there are no SemVer violations before releasing.
+      # https://github.com/obi1kenobi/cargo-semver-checks
+      - name: Check semver
+        uses: obi1kenobi/cargo-semver-checks-action@v2
+        with:
+          feature-group: default-features
+          features: pool
+
+      # Another check with the mutually exclusive tls-rustls feature enabled.
+      - name: Check semver
+        uses: obi1kenobi/cargo-semver-checks-action@v2
+        with:
+          feature-group: only-explicit-features
+          features: tls-rustls,pool
+
+
       - name: Deploy to crates.io
         if: github.event_name == 'push' && github.ref == 'refs/heads/main'
         run: cargo publish
         env:
-          CARGO_REGISTRY_TOKEN: ${{ secrets.CRATES_TOKEN }}
+          CARGO_REGISTRY_TOKEN: ${{ secrets.CRATES_TOKEN }}