doc: add Travis badge

sbinet · sbinet · commit 5561e0f6d238 · 2019-01-18T14:16:08.000+01:00
diff --git a/README.md b/README.md
@@ -1,7 +1,7 @@
 go-python
 =========
 
-[![Build Status](https://drone.io/github.com/sbinet/go-python/status.png)](https://drone.io/github.com/sbinet/go-python/latest)
+[![Build Status](https://travis-ci.org/sbinet/go-python.svg?branch=master)](https://travis-ci.org/sbinet/go-python)
 [![Build status](https://ci.appveyor.com/api/projects/status/n0ujg8no487a89vo/branch/master?svg=true)](https://ci.appveyor.com/project/sbinet/go-python/branch/master)
 
 Naive `go` bindings towards the C-API of CPython-2.
