add build status badge

README.md

@@ -3,7 +3,10 @@
 
 This repository contains two separate API plugins for phpList, the REST API Plugin v1 and v2. 
 
-v1 is no longer maintained and, while functional, should be considered depreciated.
+[![Build Status](https://travis-ci.org/phpList/phplist-plugin-restapi.svg?branch=master)](https://travis-ci.org/phpList/phplist-plugin-restapi)
+
+v1 is stable and will take PRs and bugfixes. 
+
 v2 is under active development and should be used and extended where possible.
 
 Both plugins are contained within the `plugins` folder, along with respective documentation and plugin-specific tests.