Add travis badge

Author: Ilya Radchenko

README.md

@@ -1,7 +1,10 @@
 strider-gitlab
 ==============
+
 This plugin provides seamless integration between [Strider](https://github.com/Strider-CD/strider) and [GitLab](https://github.com/gitlabhq/gitlabhq). It enables you to add GitLab repositories to Strider and it hooks up necessary webhooks in order to automatically test on commits.
 
+[![Build Status](https://travis-ci.org/Strider-CD/strider-gitlab.svg)](https://travis-ci.org/Strider-CD/strider-gitlab)
+
 contributors
 ============
   * Martin Ericson (http://www.devbox.com)