Update badge in readme to use GitHub actions.

Author: fancycode

README.md

@@ -4,7 +4,7 @@
 * **7-Zip** Copyright (C) 1999-2010 Igor Pavlov
 * **LZMA SDK** Copyright (C) 1999-2010 Igor Pavlov
 
-[![Linux Build Status](https://travis-ci.org/fancycode/pylzma.svg?branch=master)](https://travis-ci.org/fancycode/pylzma)
+[![Linux Build Status](https://github.com/fancycode/pylzma/workflows/test/badge.svg)](https://github.com/fancycode/pylzma/actions)
 [![Windows Build Status](https://ci.appveyor.com/api/projects/status/5a7k7v9k2a0eiuom/branch/master?svg=true
 )](https://ci.appveyor.com/project/fancycode/pylzma)