fix codecov action (#36)

Author: devanshshukla99

.github/workflows/main.yml

@@ -29,7 +29,7 @@ jobs:
       - name: Running tox
         run: |
           tox -e ${{ matrix.toxenv }}
-      - uses: codecov/codecov-action@v1
+      - uses: codecov/codecov-action@v3
         with:
           fail_ci_if_error: true
           files: coverage.xml