[README] add circleci status badge

diff --git a/README.md b/README.md
index 7fd1846..99b8444 100644 (file)
--- a/README.md
+++ b/README.md
@@ -1,6 +1,7 @@
 aubio
 =====
 
+[![CircleCI build status](https://circleci.com/gh/aubio/aubio.svg?style=shield)](https://circleci.com/gh/aubio/aubio "CircleCI build status")
 [![Appveyor build status](https://img.shields.io/appveyor/ci/piem/aubio/master.svg)](https://ci.appveyor.com/project/piem/aubio "Appveyor build status")
 [![Commits since last release](https://img.shields.io/github/commits-since/aubio/aubio/latest.svg)](https://github.com/aubio/aubio "Commits since last release")