Merge pull request #278 from webpack/ci/codecov

use codecov action

Author: sokra

.github/workflows/test.yml

@@ -33,4 +33,4 @@ jobs:
       - run: yarn --frozen-lockfile
       - run: yarn cover:ci
       - if: ${{ matrix.os != 'windows-latest' }}
-        run: bash <(curl -s https://codecov.io/bash) -X gcov
+        uses: codecov/codecov-action@v1