Update CI (#3)

PR to update CI using the recommendation from [julia-processcoverage README](https://github.com/julia-actions/julia-processcoverage).

`julia-action/julia-uploadcodecov` is deprecated as mentioned [here](https://github.com/julia-actions/julia-uploadcodecov). The recommendation is to use `julia-actions/julia-processcoverage` in combination with `codecov/codecov-action`.

Author: kimlaberinto

.github/workflows/CI.yml

@@ -45,7 +45,7 @@ jobs:
             ${{ runner.os }}-
       - uses: julia-actions/julia-buildpkg@v1
       - uses: julia-actions/julia-runtest@v1
-      - uses: julia-actions/julia-[email protected]
-        if:  ${{ startsWith(matrix.os, 'ubuntu') && (matrix.version == '1') }}
-        env:
-          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+      - uses: julia-actions/julia-processcoverage@v1
+      - uses: codecov/codecov-action@v2
+        with:
+          files: lcov.info