Fix logo.

README.md

@@ -1,7 +1,7 @@
 ![Custodian logo](https://raw.githubusercontent.com/materialsproject/custodian/master/docs/assets/custodian_logo.png)
 [![GitHub license](https://img.shields.io/github/license/materialsproject/custodian)](https://github.com/materialsproject/custodian/blob/main/LICENSE)
 [![Linting](https://github.com/materialsproject/custodian/workflows/Linting/badge.svg)](https://github.com/materialsproject/custodian/workflows/Linting/badge.svg)
-[![Testing](https://github.com/materialsproject/custodian/actions/workflows/pytest.yml/badge.svg)](https://github.com/materialsproject/custodian/actions/workflows/test.yml)
+[![Testing](https://github.com/materialsproject/custodian/actions/workflows/test.yml/badge.svg)](https://github.com/materialsproject/custodian/actions/workflows/test.yml)
 [![Downloads](https://pepy.tech/badge/custodian)](https://pepy.tech/project/custodian)
 [![codecov](https://codecov.io/gh/materialsproject/custodian/branch/master/graph/badge.svg?token=OwDQVJnghu)](https://codecov.io/gh/materialsproject/custodian)