Add Codecov coverage integration

Author: Adekunle Aina

.github/workflows/test.yml

@@ -20,9 +20,8 @@ jobs:
       # Run tests with coverage
       - run: pytest -q --cov=fastmdanalysis --cov-report=xml
 
-      # Upload to Codecov
+      # Upload to Codecov (no token needed)
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v3
         with:
-          file: ./coverage.xml
-          fail_ci_if_error: true
+          file: ./coverage.xml