update codecov action to v1.0.15

Author: pabra

.github/workflows/unit-tests.yml

@@ -59,7 +59,7 @@ jobs:
         run: npm run test:after-commit
 
       - if: ${{ matrix.os == 'ubuntu-latest' || matrix.node == 12 }}
-        uses: codecov/[email protected].14
+        uses: codecov/[email protected].15
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           flags: unittests