Update README.md

Add build status icon

Author: sanderv32

README.md

@@ -1,3 +1,5 @@
+[![Build Status](https://ci.jenkins.io/buildStatus/icon?job=Plugins/gogs-webhook-plugin/master)](https://ci.jenkins.io/blue/organizations/jenkins/Plugins%2Fgogs-webhook-plugin/activity/)
+
 Gogs-Webhook Plugin
 ===================
 
@@ -11,4 +13,4 @@ Example how your the webhook in Gogs should look like:
 
 ### About integration tests
 
-This project has some integration tests available. For more details see the [dedicated readme](about_integration_tests.md).
+This project has some integration tests available. For more details see the [dedicated readme](about_integration_tests.md).