Undercover added to CI

Author: EgorBazhenov

.github/workflows/ci.yaml

@@ -135,4 +135,7 @@ jobs:
         if: github.ref == 'refs/heads/main'
         run: ./cc-test-reporter upload-coverage
         env:
-          CC_TEST_REPORTER_ID: ${{ secrets.CC_TEST_REPORTER_ID }}
+          CC_TEST_REPORTER_ID: ${{ secrets.CC_TEST_REPORTER_ID }}
+
+      - name: Check code changes coverage
+        run: run ./bin/undercover