Bump codecov/codecov-action from 1.5.2 to 2.0.1

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 1.5.2 to 2.0.1.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/master/CHANGELOG.md)
- [Commits](https://github.com/codecov/codecov-action/compare/v1.5.2...v2.0.1)

---
updated-dependencies:
- dependency-name: codecov/codecov-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/main.yml

@@ -72,4 +72,4 @@ jobs:
       - name: Generate code coverage
         run: cargo llvm-cov --all-features --lcov > lcov.info
       - name: Upload coverage report to Codecov
-        uses: codecov/codecov-action@v1.5.2
+        uses: codecov/codecov-action@v2.0.1