Update README.md

Author: ablaom

README.md

@@ -3,7 +3,7 @@ Repository implementing MLJ interface for
 [Clustering.jl](https://github.com/JuliaStats/Clustering.jl) models.
 
 
-[![Build Status](https://travis-ci.com/alan-turing-institute/MLJClusteringInterface.jl.svg?branch=master)](https://travis-ci.com/github/alan-turing-institute/MLJClusteringInterface.jl)
+[![Build Status](https://github.com/alan-turing-institute/MLJClusteringInterface.jl/workflows/CI/badge.svg)](https://github.com/alan-turing-institute/MLJClusteringInterface.jl/actions)
 [![Coverage](http://codecov.io/github/alan-turing-institute/MLJClusteringInterface.jl/coverage.svg?branch=master)](https://codecov.io/gh/alan-turing-institute/MLJClusteringInterface.jl)
 [![Code Style: Blue](https://img.shields.io/badge/code%20style-blue-4495d1.svg)](https://github.com/invenia/BlueStyle)