add ci build status badge to readme

Signed-off-by: Gaetan de Villele <gdevillele@gmail.com>
2017-05-03 13:27:10 -07:00 · 2017-05-03 13:27:10 -07:00 · 92094372d3
--- a/README.md
+++ b/README.md
@ -1,3 +1,5 @@
+[![build status](https://circleci.com/gh/docker/cli.svg?style=shield)](https://circleci.com/gh/docker/cli/tree/master)
+
 docker/cli
 ==========