Update CI.yml (#12)

As mentioned in: https://github.com/codecov/codecov-action , codecov-action@v1 will be deprecated/sunset on February 1, 2022.

There are a few breaking changes mentioned in the codecov-action README.md, but I don't think this workflow uses any of the breaking changes mentioned.

--

As mentioned in README for codecov-action, token is not required for public repos

Author: kimlaberinto

.github/workflows/CI.yml

@@ -49,7 +49,6 @@ jobs:
       - uses: julia-actions/julia-buildpkg@v1
       - uses: julia-actions/julia-runtest@v1
       - uses: julia-actions/julia-processcoverage@v1
-      - uses: codecov/codecov-action@v1
+      - uses: codecov/codecov-action@v2
         with:
-          token: ${{ secrets.CODECOV_TOKEN }}
           file: lcov.info