fix coverage badge in readme

Signed-off-by: tenzen-y <[email protected]>

Author: tenzen-y

README.md

@@ -1,6 +1,6 @@
 # Kubeflow Training Operator
 
-[![Build Status](https://travis-ci.org/kubeflow/tf-operator.svg?branch=master)](https://travis-ci.org/kubeflow/tf-operator)
+[![Build Status](https://github.com/kubeflow/training-operator/actions/workflows/test-go.yaml/badge.svg?branch=master)](https://github.com/kubeflow/training-operator/actions/workflows/test-go.yaml?branch=master)
 [![Coverage Status](https://coveralls.io/repos/github/kubeflow/tf-operator/badge.svg?branch=master)](https://coveralls.io/github/kubeflow/tf-operator?branch=master)
 [![Go Report Card](https://goreportcard.com/badge/github.com/kubeflow/tf-operator)](https://goreportcard.com/report/github.com/kubeflow/tf-operator)