Migrated codecov/codecov-action from v1 to v2.

Author: sunaoka

.github/workflows/test.yml

@@ -36,8 +36,8 @@ jobs:
         run: vendor/bin/phpunit --coverage-clover=coverage.xml
 
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v1
+        uses: codecov/codecov-action@v2
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
-          file: ./coverage.xml
+          files: ./coverage.xml
           fail_ci_if_error: true