add link to YourKit, build status icon

README.md

@@ -1,3 +1,6 @@
+Vassal [![Build Status](https://travis-ci.com/vassalengine/vassal.svg?branch=master)](https://travis-ci.com/vassalengine/vassal)
+===
+
 The VASSAL Team is happy to announce the release of VASSAL 3.3.2.
 
 ********************************************************************************
@@ -97,3 +100,13 @@ or by email to [email protected].
 Cheers,
 
 The VASSAL Team
+
+Special Thanks To:
+-------------
+![YourKit-Logo](https://www.yourkit.com/images/yklogo.png)
+
+YourKit supports open source projects with innovative and intelligent tools
+for monitoring and profiling Java and .NET applications.
+YourKit is the creator of <a href="https://www.yourkit.com/java/profiler/">YourKit Java Profiler</a>,
+<a href="https://www.yourkit.com/.net/profiler/">YourKit .NET Profiler</a>,
+and <a href="https://www.yourkit.com/youmonitor/">YourKit YouMonitor</a>.